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Question on 208 Amax, RL17 - Updated 8/19/11

LawnMM

Harbinger of Sarcasm
Full Member
Minuteman
  • Jul 5, 2009
    5,353
    8,748
    Colorado
    Just had my rifle re-barreled from a factory SPS 20" 1:12 twist to a 24" Rock Creek 5R 1:10 twist. I'm going to break it in with my go to load of 178 Amax and 44 grains of RL15.

    However, with the longer barrel, and tighter twist, I bought the fixens to experiment with the 208 Amax. Here comes my question. My max chamber length is 2.964" to the O give. I was going to try to load them to mag length, with AI mags, at 2.890"...but ran into compression immediately at 45gr.

    So I figured I would go the tried and true method and just single feed the rounds to make the most of cartridge space. I started loading them at 44gr at 2.965 COAL, measures about 2.242 to the O give. Doing that I can hear powder moving in the case at 44 grains. I start to hear a little crunch up through 45 and 46 grains, but can still hear a little movement after seating the bullet. Not until about 47.5 or so do I hear a little crunch and no movement afterwards.

    So here is the question, I'm starting at 44 grains and moving up in half grain increments, really just looking for pressure and a rough idea of velocity at this point. As long as I'm working up if the compression increases to a point where its going to give the rifle a problem, I'll start seeing the common warning signs right? Flattened/Cratered primers, sticky bolt lift, ejector marks, etc.?

    Looking at other guys' data on here it seems everybody with a 24" or better barrel starts breaking into the 2600FPS threshold right around 47-48 grains, which is right about where I'm not hearing movement in my cases. Its not heavily compressed, I don't have to put much effort into seating the bullet, but I do hear a little crunch as a few of the sticks of powder break while seating.

    Is it any more dangerous if you move up incrementally like we always do? Should you scrap the rounds if you hear any crunch at all? Logically it doesn't seem like it would matter if you break a few sticks during seating, as long as its not totally smooshed. Even then I would think you would be ok with an incremental workup. If you get the pressure warnings because the load is starting to compress, stop.

    I can't imagine that Montana Marine and some of you other guys loading upwards of 50-51 grains, even at a COAL of 3.000 aren't getting a little crunch on seating. We're talking a difference of 0.036. Does 36/1000ths make that huge a difference? Any thoughts? Suggestions?

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Rich, I'm definitely getting some crunch at 50 gr RL17 and 3.00" oal. I don't think the compression itself is a pressure hazard, as long as the powder is relatively slow like RL17.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    For reference, this is 50gr RL-17 in fireformed/neck-sized Win brass.

    P6160021.jpg
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I'm sure you can go hotter, but 47.5 was awesome for me.


    208s.jpg


    That was out of a factory 26inch 700VLS barrel. 2625fps Average
    SD of 9fps
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I think you would be fine seating to mag length. I am running 46.4 grains of RL17 at 2.85" and I am getting 2440 out of my 19" Krieger barrel. My shooting partner has a 24" Krieger and he is getting upwards of 2600 at mag length.

    I wouldn't turn a repeater into a single shot unless I absolutely had to, but that's just my .02.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Thanks guys for the replies, and the pics help a bunch MM. I just don't know much about compression so I wanted to make sure it wasn't a deal breaker, blow your face off, sorta deal.

    My range is an hour away so I think I may load both and I'll chrono the loads and watch for pressure as I work up. Might load a bit hotter than the 48.5 too, for kicks.

    I will work up a batch of mag length as well, maybe I'll keep them separate and post pics for pressure comparison between the mag length and chamber length rounds of the same powder load.

    I appreciate the replies fellas, I will let you know how it goes!

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Rock Creeks tend to run fast, so you probably will attain the speeds you want at mag length or get something ridiculously fast at 3.000". Let us know the results.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I'm currently working with the 208's in a 1-10" twist Rock myself.

    I am obtaining great accuracy with the Varget during my ladder tests. My initial ladder was showing a helluva node hovering around max for Hogdon's data (42.0gr compressed) for the 200's. I ran with Hogdon's data from start to just over max (again, compressed) and am running the loads jammed .01" in the lands. Here's my initial ladder test.......

    Shots 8-10 @ 300 yards came in at .786" center-to-center

    IMAG0170.jpg


    Here's a refinement on the above node at 425 yards.......

    Shots 1-3 @ 425 yards netted a 1.254" center-to-center

    downloadfile-2.jpg


    Not to hijack your thread, but I steered away form RL for the 208's due to having to run it as hot and the lack of temperature sensitivity of the Varget. I haven't chrono'd the Varget loads yet, but as is known, the Rock's tend to run a tad faster. With that, book data is showing just shy of 2450fps. If I can keep it above 2400fps with the Varget and the accuracy is there, I'll be tickled. The 208's at 2400 will easily make it to 1K and do so without the pressure. Even over 1/2gr over max, I'm not getting anything alarming for pressure. The only thing I noted was a faint amount of primer flattening.

    Planning on a full write-up on the 208's and Varget after I get to set down and shoot groups with the loads in my 425 yard ladder. More to follow.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Good information here, its why I ask, somebody's already done it, or something close, and there's always a wealth of good info here. I'm grabbin a quick bite and feeding the dogs and then I'm gonna head out and see what happens.

    I elected to shorten what I had loaded for chamber length down to mag feed length, as thats what I'm really after. I'm going to break it in with 20 rounds of my current load then I will start chronographing the 208s and RL17. Later in the week I will go back out for accuracy testing based off of comments here and my results from today. Will check back this evening.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Don't worry about the crunch unless you are seeing pressure signs. I worked up to 49gr into Win cases at 2.95". 49.5gr pushed the bullets back after seating.

    I stopped goofing around with them because my AI mags aren't modded and won't feed the 208's at that length.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Hey chaps, I'm also half way thru varget development with the 208's..
    I have started at AI mag length, and so far settled on 41.3 gr varget in Lap body sized brass.. No pressure signs, and right on 2400fps
    With 20 ES and 6 SD so far..
    It was clover leafing test groups, so I'm running with it for a while and see how they do past 100yrds..

    This out of a 26" 1/10, I'm also interested in anyone else running these around AI mag length..

    Has anyone tried them with vv550??
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Don't sweat the compression!

    I also ran up to 51gr. of RL17 at mag length with the Berger 210's. I use a drop tube for loading so I "may" get a little better fill than some others. The drop tube is an old arrow shaft about 24" in length. I attached a small funnel to the top and chamfered the bottom. I hold the arrow and the case aligned on my knee and pour slowly. That's it.

    There is a sweet node at 47.5 gr. that is just a little crunchy. It should be around 2500 fps. I just shot one of them today in fact to check it out, and it is the exact POI at 100 as the 168 SMK/ IMR 8208 load that shoots great, too.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Okay here we go with results from today...

    Started with a quick workup on my existing 'go to' load of 178gr Amax, Winchester Brass, CCI Primers, and 44gr of RL15. New barrel, I like to work up real quick to make sure the load doesn't put undue stress on a barrel it wasn't originally worked up in.

    41.5gr
    -2440
    -2460

    42.0gr
    -2479
    -2495

    42.5gr
    -2531
    -2493

    43.0gr
    -2539
    -2563

    43.5gr
    -2582
    -2594

    44.0gr (already had em loaded, shot 10 to check the numbers)
    -AV 2617
    -SD 26.3
    -ES 79.0

    44.0gr (Shot a second string when finishing for the day)
    -AV 2608
    -SD 22.3
    -ES 72.0

    The ES/SD numbers on this load aren't so good. They were single digit SD on the old barrel. Looks like I'm going to need to do some more development on my previous load to get it dialed in on the new barrel. Best group I could pull out of it was a little under .75MOA, I'm looking for .5 or .25 with this rig after the barrel and smith work.

    208 Amax results, RL17, Winchester brass, CCI 200s, loaded at 2.890 COAL, max that would fit in a regular AI mag, I think its also the max that will load with the feed ramp, so if I don't single feed, I'm stuck at 2.890. Here we go...

    43.0gr
    -2368
    -2368

    43.5gr
    -2400
    -2364

    44.0gr
    -2350
    -2365

    44.5gr
    -2416
    -2415

    45.0gr
    -2425
    -2411

    45.5gr
    -2467
    -2448

    46.0gr
    -2479
    -2468

    46.5gr
    -2536
    -2528

    47.0gr
    -2528
    -2499

    47.5gr
    -2566
    -2554

    48.0gr
    -2594
    -2588

    48.5gr
    -2480
    -2591 (primers still intact, no ejector wipe, sticky bolt)

    The 48.0gr load is probably where I will start accuracy testing. Its coming in 12fps or less under the 2600fps mark, no signs of any pressure, and the two rounds I loaded and fired for the testing only had a 6fps difference in velocity. I'm going to try and see what happens with the 48.0gr load. I'm going to start there, load a 5 round string at 48.4 and 48.3 to see if it tightens up a little lower, and I'm going to load from 48.0 up to 48.6, maybe 48.7, and see if I get good velocity consistency in that range.

    I will probably do it Wednesday, I'm planning to do the testing at 300 yards, and I will shoot each powder charge in 5 shot strings to check accuracy. I will post photos of the results from that test. Wasn't much to show on this one as I was really only looking for speed and pressure before I started closing in on the accuracy node. The tightest group closest to 2600fps will be the winner, thats my goal.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Done with the load up. I have 5 round strings loaded, from 47.8gr to 48.7gr in 0.1gr increments. I will chrono those while I shoot 5 round groups at 300yds on Wednesday. See what I come up with.

    As a side note, any of you boys try loading the RL17 under the 178 Amax or the 175 Sierra rounds? I'm wondering what sort of speed bump it might yield. I will try and work those up later this week also. I'm on vacation so I'm trying to get my load development projects done while I have the extra time.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Approaching 2600 fps at mag length is pretty nice! If accuracy is good, that will be a nice LR load for sure.

    The ES on the 48.5gr load looks excessive at over 100 fps, maybe a mistype??
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Thats what the chrono recorded. I don't know if that was a bad powder charge or what. I noticed that as you stuff these long 208s in the cases that are pretty full of powder that the projectiles will require different micrometer adjustments to get them seated to the same depth, different amounts of crunch I presume. I found that running the lever twice helps seat everything more uniformly without the extra adjustment, but I figured that out today after the fact.

    I don't know if it had to do with seating depth, or if I goofed a powder charge or what. I measure each charge though so I doubt the charge was off. I'm thinking I dropped one of the lower charged rounds into the slot next to a higher one. In short, I'm thinking that wasn't a 48.5gr round.

    I'm hoping to get to 2600fps at mag length on wednesday minus the sticky bolt, which I think is doable. I will find out using more rounds per string later this week. I think the sticky bolt was a fluke, the primers were fine and no sign of ejector wipe.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Sounds like you are getting good speeds. I was at 10.6 mils, 3000da, with 2440fps this weekend. The nice thing was that 427Cobra was shooting beside me and was running a 260 with 140 amax and his wind holds were almost identical to mine. Hard to beat a 308 with a wind close to the 260 ....... The trade off was after he shot it, man this thing kicks a little, lol.

    Keep up the load dev and keep us posted. You will be pleased with the long range results.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I agree with running the ram handle twice. I also just bought the 208 AMAX seating insert from Hornady. This in conjunction with the micrometer seating stem makes it a simple operation.

    When I wasn't using the 208 insert, I was getting funny looking bullet noses after some compression. That was without the drop tube. I think the drop tube will let you put another grain or so into the case before you feel the crunch.

    This powder is temp sensitive. It appears to be like the RL25 I used in my RUM a few years back. If you are running a hot load and the temp goes up 10*-20* F, you might get into trouble. That goes with leaving rounds in a hot chamber or the sun, etc.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I have heard people say the same thing about RL15 and I havent experienced much of a swing. The good news is its mid summer and quite warm out where im doing the load development at CRC. If the load works now cooler temps shouldnt be an issue. Workups in mid winter near max charge, might wanna watch that.

    I might make myself a drop tube and see if that helps too. On the wind dope being close to 260 its one of the reasons I am developing the load. I like the wind cheater BC but with 308 barrel life and reloading costs =)

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I just reloaded some 208g AMAX using Reloader 22 for my 300 winmag. I also have been noticing that seating to Ogive OAL requires tiny mm adjustments to the seating die in order to maintain consistent OAL. Im using 70 grains, and running jammed at 3.915. Plan on chrony maybe next weekend. These rounds are punching paper at 200-300yrds, with groups well under MOA
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Good on ya for developing summer loads. I shot 51 gr of RL17 in my rifle in the winter in a mag length chamber. I thought diamonds would come out of the case if I opened it after seating.

    The .308 is great! The 208's make it that much better.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jig Stick</div><div class="ubbcode-body">I just reloaded some 208g AMAX using Reloader 22 for my 300 winmag. I also have been noticing that seating to Ogive OAL requires tiny mm adjustments to the seating die in order to maintain consistent OAL. Im using 70 grains, and running jammed at 3.915. Plan on chrony maybe next weekend. These rounds are punching paper at 200-300yrds, with groups well under MOA </div></div>

    Try running your reloading press handle a second time, if its set with a micrometer adjustable seating die it shouldn't matter if you run it 83 times, it shouldn't seat any deeper than you have it set. However, that first run of the handle seems to crunch the bullet down in, compress and break up the powder a bit, and a second pull gets it closer to where it 'ought to be.

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">Good on ya for developing summer loads. I shot 51 gr of RL17 in my rifle in the winter in a mag length chamber. I thought diamonds would come out of the case if I opened it after seating.

    The .308 is great! The 208's make it that much better. </div></div>

    Well, its more coincidence than design. I'd be doing the work in the winter too if thats when I happened to get the barrel work done. It does simplify things to develop the loads in the summer though, lower temps = lower pressure, so if your load works fine at 90ish degrees in the summer, should be fine in the 40s over the winter.

    I'm really looking forward to getting these 208s running smooth in my rifle. The BC is just great. At 1k it drops about 60 inches less with maybe 40%ish less wind drift. Flatter trajectory and less wind drift, sounds great to me! The new twist and barrel length help too =)

    By far the best feature, I can find the 208s for about 10 dollar less per box of 178s and 175s locally. The internet is your friend.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Okie dokie, results from the trip. I stopped half way through the 50 rounds I had loaded because I had achieved, and exceeded, my goal for speed on the load. I'm also going to say that, unfortunately, my accuracy testing will require a re-do. I'm rusty after some time away from the range. The bugs today were unreal, I was eaten alive today, even after streaks of deet painted on my black t-shirt making it look like camouflage.

    I will head back out there on Friday with a more honed in idea on an accurate load and will shoot from a covered position that will hopefully cut down on some of the critters. I'm also going to bring a full set of long pants and sleeves as well. It wasn't a total loss though, I managed good chrono recording on the loads and have good numbers to work with at the reloading bench today and tomorrow before I head out again.

    Here we go...

    DSCN0702.jpg


    5 Shots @ 47.8gr
    -AV 2597fps
    -SD 10.3
    -ES 32.0

    DSCN0703.jpg


    5 Shots @ 47.9gr
    -AV 2610fps
    -SD 17.1
    -ES 49.0

    DSCN0705.jpg


    5 Shots @ 48.0gr
    -AV 2618fps
    -SD 18.8
    -ES 58.0

    DSCN0706.jpg


    5 Shots @ 48.1gr
    -AV 2635fps
    -SD 9.0
    -ES 22.0

    The last string shows the most promise with the best numbers, despite being one of the bigger groups, the numbers, on paper at least, look great. No signs of pressure on the primers or case head. I had two rounds give me a slight sticky bolt but it was quite random and not typical of any one given string. I did run into feeding issues, I had the rounds loaded to 2.160 to the O give but I'm gonna need to seat them back another .002 or so to make sure they clear the feed ramp from the magazine.

    I will shoot at 550yds on Friday at my steel target, 10"W x 17"L and re-paint between strings and photograph and measure the group sizes. I'm sure it will tighten up when I'm a bit more focused and a little less chewed on. I'm going to bring some rounds loaded to 48.1gr since it had the best numbers and I will bring a few loaded to 47.8gr as it came in second. I think the grouping will be more along the lines of what I'm after on Friday. I tell ya, even a few weeks off and you start slipping on the fundamentals. Precision rifle shooting is definitely a perishable skill!

    Temp was 95F with a DA of about 7800ft measured by my Kestrel, 35% humidity. It was hot!

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Those results are interesting. What primer are you using? I have been using a CCI BR2 (expensive CCI 200) and never had large ES/SD numbers like yours. I wonder what gives? The best node for accuracy and chrono numbers was 47.5 for me. Single digits all the way. The next node up was 49.0 after that it was 50.1, and that was the load I settled on in a previous iteration of my Savage. I will begin the load work up again for this new chamber and report back. Like I said in an earlier post, the 47.5 shot fine, and in fact the same POI/POA as the 168's. I only loaded up one just to see. I didn't even bother to find where it hits the lands either. i just made it 2.850 OAL, and left it at that.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">Those results are interesting. What primer are you using? I have been using a CCI BR2 (expensive CCI 200) and never had large ES/SD numbers like yours. I wonder what gives? The best node for accuracy and chrono numbers was 47.5 for me. Single digits all the way. The next node up was 49.0 after that it was 50.1, and that was the load I settled on in a previous iteration of my Savage. I will begin the load work up again for this new chamber and report back. Like I said in an earlier post, the 47.5 shot fine, and in fact the same POI/POA as the 168's. I only loaded up one just to see. I didn't even bother to find where it hits the lands either. i just made it 2.850 OAL, and left it at that. </div></div>

    CCI 200's. I have a single pack of BR2s but never found much difference, but then I was chronographing those loads either. I might load some of those up tomorrow for testing on Friday just for shits and giggles. I'm also finding that the compression at mag length, standard mag length anyway, is a bitch. It adds A LOT of extra time on the bench because due to the varying amounts of powder compression and the subsequent fine tuning of the micrometer on the seating die.

    I tried loading them at chamber length, 2.960", and set the die and loaded 5 and they were all spot on. I have an alpha mag inbound, I may go back to my gunsmith while still on vacation and have the feed ramp altered with a little cone cut into it so the longer rounds clear. Then I can have my mag cake and eat it too without constant readjustment trying to get them to fit standard mags while fighting varying amounts of powder compression on every single round.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I use the RCBS Chargrmaster, Hornady dies and a long drop tube. The compression on mine doesn't vary at all. The OAL with compression is not the same as with no compression. If they are REALLY compresses, the same adjusted OAL will yield a longer OAL, and the die needs to be adjusted even shorter to compensate for crunch. A few duns of the handle too.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    if you get into all this crunchy stuff, you oal consistency will suffer. 208 is a great bullet, but again i think it belongs in a 300wm.are any of you guys shootin steel at 1k, if so what does the proj. look like after impact @1k, you gotta be redlining those 308's trying to push these things the distance,just my 2, whatever blows yer skirt up though
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">I use the RCBS Chargrmaster, Hornady dies and a long drop tube. The compression on mine doesn't vary at all. The OAL with compression is not the same as with no compression. If they are REALLY compresses, the same adjusted OAL will yield a longer OAL, and the die needs to be adjusted even shorter to compensate for crunch. A few duns of the handle too. </div></div>

    I understand that you need to readjust the die with the powder compression, the problem is you have to readjust with EVERY round. At least with standard mag length and 48+gr of powder.

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: procovert45</div><div class="ubbcode-body">if you get into all this crunchy stuff, you oal consistency will suffer. 208 is a great bullet, but again i think it belongs in a 300wm.are any of you guys shootin steel at 1k, if so what does the proj. look like after impact @1k, you gotta be redlining those 308's trying to push these things the distance,just my 2, whatever blows yer skirt up though </div></div>

    I will try to find a projectile for you after I take the load to 1k later this weekend, maybe next week. You arent redlining the 308 with these loads, its sort of the point of the thread. I shot at 95F in the sun today with no pressure signs on any of the spent shells and im pushing the 208s at 2600+fps. 2400 is more than enough to get them to 1k. Im just tweaking for accuracy and ease of reloading at this point.

    Rich

    **Edited to add, I can probably find one thats hit the dirt, FFL has a good point though, they tend to break up on impact. My 178's would always blow apart on a hit and they were moving about 50fps slower. I did occasionally find a miss that had hit the soft clay and survived.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    No readjustment necessary. Once you find the "spot", it's good to go. I measure the ogive on each round too. And I've yet to find a spend bullet that has impacted steel at any distance, little bits maybe, but hardly anything discernible as a bullet.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">No readjustment necessary. Once you find the "spot", it's good to go. I measure the ogive on each round too. And I've yet to find a spend bullet that has impacted steel at any distance, little bits maybe, but hardly anything discernible as a bullet. </div></div>

    I will measure some of the projectiles then and see if they are off. Or maybe I just need a better seating die. My experience has been that the powder doesn't compress very evenly and even after running the handle twice, or even thrice, some rounds will seat to the length you want, and others, many others, are stubborn and require additional adjustment to get them seated to the proper OAL.

    I'm using an RCBS competition seating die with the micrometer adjustments. Which ones are you guys using? Maybe I need one that holds its setting better. There is no movement on the micrometer dial but maybe something internal is allowing the bullet to resist seating. I assumed it was the varying degrees of powder settling and compression.

    Less settling and compression needs more die adjustment to achieve the same OAL. Its not an issue at chamber length though and thats still shorter than what the Alpha mags will accept so I'm going to look into modifying the feed ramp.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I made it out today, rather than Friday, and was pretty pleased with the results...

    Here was a group with the 208s and 48.3gr of RL17

    DSCN0725.jpg


    Probably could have done better but I'm still rusty. Spent some time on the fundamentals first and that helped a lot. Also shot this next group with my prior load, 178 Amax and 44gr RL15, from the bench...

    DSCN0726.jpg


    The shot in the low left of the bull is a 208 that I confirmed the zero with before switching to the 178s off the bench.

    I expect it will be even better next time I go. I think part of the results were me getting back to focusing on the basics and part is perhaps the barrel still breaking in a bit.

    My numbers were sporadic again...

    5 shot string of 208s

    AV 2624
    SD 20.9
    ES 57.0

    Another...

    AV 2648
    SD 15.3
    ES 44.0

    Dunno what that was, I thought it may be the temp change during my session? I was meticulous as all hell with the powder charges and I'm still seeing a pretty sporadic spread on the numbers. I will go out again on Monday, and I plan to load up 10-20 more rounds using BR2 primers and I'm going to use 1x fired brass and prep the flash holes. See if that makes a difference.

    Still, its approaching 1/2MOA, little more attention to detail on the bench and a bit more focus on the fundamentals and I think I can get it there.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    Range day scheduled Thursday after a camping trip I'm going on tomorrow. I'm loading up the same load with some CCI BR2's to see if that makes a difference, brass is also sized and prepped. The previous groups were new winchester brass, typically I just run the expander ball through the mouth area to make it uniform and I chamfer/deburr.

    I don't size the new brass or trim it as its usually quite close to spec and its going to be fireformed after the first go around anyway. I will post back with comparison groups of new brass with cci 200s and 1x fired/formed with BR2s. Should be interesting.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body">Looks like you're getting dialed in. </div></div>

    Trying to...

    Any ideas on the spread with the SD/ES numbers other than primers? Is the powder temp sensitive enough to affect velocity shot to shot, even when single fed? How stable were your numbers when you worked up your load?

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I think the only other thing that the ES issue could be might have something to do with neck tension. Other than that, I don't know. Maybe a CCI 250 might be what she needs.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">I think the only other thing that the ES issue could be might have something to do with neck tension. Other than that, I don't know. Maybe a CCI 250 might be what she needs. </div></div>

    Would possibly a higher or lower neck tension bring down ES with this loading.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I want to say more neck tension. The only reason I bring it up is the same effect in magnum pistols. I'd try a magnum primer, too.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LawnMM</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body">Looks like you're getting dialed in. </div></div>

    Trying to...

    Any ideas on the spread with the SD/ES numbers other than primers? Is the powder temp sensitive enough to affect velocity shot to shot, even when single fed? How stable were your numbers when you worked up your load?

    Rich </div></div>

    My numbers tightened up when I got close to the top end. The last 5-shot string I clocked from the 20.5" 308 with 50gr RL17 from a clean cold bore went like this: 2599, 2611, 2617, 2618, 2618.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffl medic</div><div class="ubbcode-body">I think the only other thing that the ES issue could be might have something to do with neck tension. Other than that, I don't know. Maybe a CCI 250 might be what she needs. </div></div>

    I wonder if its a case of the tension being higher than it should be with some of the powder compression. Jamming those projectiles in might be upping the neck tension more than it should. Could be a primer thing too, are the 250's magnum primers? Whats the idea behind those?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: paul T</div><div class="ubbcode-body">Would possibly a higher or lower neck tension bring down ES with this loading. </div></div>

    Maybe, will probably try that next depending what I see with the BR2s, not planning to Chrono them, just check for accuracy differences. If I see anything noticeable I will load some more for chrono testing. I might try some of the other ideas coming up here at that point too.

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LawnMM</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body">Looks like you're getting dialed in. </div></div>

    Trying to...

    Any ideas on the spread with the SD/ES numbers other than primers? Is the powder temp sensitive enough to affect velocity shot to shot, even when single fed? How stable were your numbers when you worked up your load?

    Rich </div></div>

    My numbers tightened up when I got close to the top end. The last 5-shot string I clocked from the 20.5" 308 with 50gr RL17 from a clean cold bore went like this: 2599, 2611, 2617, 2618, 2618. </div></div>

    Hmm, may have to try that also. What seating dies are you guys using? I have one of the RCBS micrometer competition dies but its not really up to the task with the powder compression loads. The seating depth becomes inconsistent. Maybe I need to fashion a long drop tube or something of the sort to see if I can settle the powder more as the cartridges are being loaded.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    I use a Lee seating die, and also a Redding competition seating die. I can't tell any difference in accuracy.

    Sometimes the irregular oal is because the heavy compression actually pushes the bullet back out a bit. I've had some rounds "grow" overnight. I moly my bullets and that is surely a factor by 'lubricating' the bullet.
     
    Re: Question on 208 Amax, RL17, and compressed loads

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body">I use a Lee seating die, and also a Redding competition seating die. I can't tell any difference in accuracy.

    Sometimes the irregular oal is because the heavy compression actually pushes the bullet back out a bit. I've had some rounds "grow" overnight. I moly my bullets and that is surely a factor by 'lubricating' the bullet. </div></div>

    I haven't really seen any grow with the powder pushing back, you are loading a few grains higher than I am still. The neck tension idea is intriguing, but I'm not really set up for that. I may invest in some Type S bushing dies for sizing and see if I can get more consistent neck tension out of my loads. Then I may try adjusting the tension up or down depending what seems like it may help.

    I would think a bit more tension would help with the seating consistency, a little extra gription on the bullet from the neck might alleviate some of the issues with OAL consistency and neck tension consistency, all of which may be contributing to the higher SD/ES numbers.

    Rich
     
    Re: Question on 208 Amax, RL17, and compressed loads

    So I shot this load today at the CRC prairie dog match and it went pretty well. I had zero verified dope just a JBM card I made for an idea on a starting point. Did okay I think, had several misses that were my own fault for using wind holds I developed a feel for using 178 amax rounds...wound up overcompensating and missing as a result.

    Did a little rough match at the range against the dope and when I realized I was looking at less than 2 inches of drift at 550 yards with a 10mph wind, my scores went up. I just stopped compensating for the wind for most of the match. Only had to do a slight hold, 1/4 mil at 425yds and 1/2 mil at 550 when the wind kicked way up.

    I checked my sizing settings on my die and the tension seems correct. The rounds measure .332" loaded, and the die was sizing the necks to .330"...that seems correct, but for those of you that dabble in neck sizing and tension, could it be on the low side? Or maybe high?

    I sold a couple things and have some funds for some decent sizing dies. My necks are in the .343-345" range after being fired so I will need to tension them in two steps, as per the current trends on the subject. I don't want to use a full length die twice, as I will likely be working the brass more than I need to. I'm planning on buying a Redding Type S bushing die for neck sizing, and one for full length sizing, and bushings set for .330 and .337 for my brass. I will size the necks halfway to the goal with the neck sizer, then bring them the rest of the way running the brass through the full length sizer.

    Anybody thinking I should set my sights on .229 or maybe .331 for a final neck size?

    Rich
     
    Re: Question on 208 Amax, RL17 - Update & New Question

    Update 8/19

    Been to the range a few times since the last post trying to iron things out a bit. I discovered part of my issue was my own lack of attention to detail. The 48.1gr load I was getting an SD of 9fps with was what I meant to develop and somewhere along the line my brain added two tenths of a grain and I was loading them at 48.3gr.

    I loaded some at 48.1gr and chronographed it last week and was able to retain the same 9fps SD. Tried some more this week with some accuracy testing against different primers.

    2011-08-18_15-08-40_962.jpg


    Top left was the first group of the day with CC BR2 primers. Low left was CCI 200s, Top middle BR2s, Top right 200s.

    I'm finding no difference in accuracy. What I did learn is that rather than breaking the trigger to anticipate recoil, I found I was doing it to avoid another breathing cycle if I didn't get all the way through the trigger squeeze on the first one. Wound up pushing the shot and the groups opened up accordingly.

    To test that theory I fired one last round at the top right target, but I made sure to take my time on the squeeze and if I needed another breathing cycle to get through it I used it...right through the center of the bulls eye. I plan to work on my breathing more with some dry fire before the next range session.

    I've also fashioned a drop tube out of a powder funnel tip for my powder measure and an actual funnel at the top of a plastic tube. It settles the powder enough at 48.1gr that I can seat the 208 Amax projectiles with one pull of the press handle and they seat consistently at the 2.960" COAL that I aim for. These rounds also fit and feed quite well through the new Type II Alpha Mags I purchased for my AICS.

    Here is the first group with calipers...

    2011-08-18_15-09-24_551-1.jpg


    The rounds are definitely 1/2 MOA capable at 100 yards despite their weight. I wanted to try them at extended distances on the high power range so I gave that a whirl. Unfortunately after getting the target set and driving to 600 yards I found the vegetation had grown high enough to obstruct view of where the target was from prone. So I had to shoot from a bench at the 1000 yard line to be high enough to see the target. I made a first round hit at 1040 yards with this load and I'm still relishing the awesome feeling that comes with that. First round hit was the one in the middle...

    2011-08-19_11-03-08_637.jpg


    Shot more and hit the sucker another 2-3 times. My steel target is 10" across so I was more than happy to manage a few MOA shots at a grand in the same session. I've lobbed more than 20 rounds of 178 amax'es at the same target in the past and not managed any hits with the winds pushing the round around and my own lack of ability making up the rest. I love these 208s they definitely do VERY well at extended ranges in the wind.

    I have my sizing dies set now also, best I could manage was getting them set for about a .004" shoulder bump from where they wind up after firing. Not as fine an adjustment as I would have liked but should still net okay brass life, I hope. I reviewed the chrono results from yesterday and found the 48.1gr load is hovering right around 2590-2595fps with SD's on the groups at 10 and 11fps. So it definitely seems to be a good load for this rifle.

    I'm hoping to reduce the SD numbers when I add a chargemaster to the stable. Should help with time spent at the bench also, should be grabbing one here in the next couple weeks. Once I get my AI mags all sold I'm going to buy more Alpha's and more 208s for the bench.

    Rich
     
    Re: Question on 208 Amax, RL17 - Update & New Question

    Good luck in your ongoing load development. I appreciate the detail with which you chronicled this. Very helpful to those of us scouring for data on the 208's.
     
    Re: Question on 208 Amax, RL17 - Update & New Question

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: daw</div><div class="ubbcode-body">Good luck in your ongoing load development. I appreciate the detail with which you chronicled this. Very helpful to those of us scouring for data on the 208's. </div></div>

    No problem. Just trying to add to the knowledge base. Should be ready to purchase a Chargemaster combo next week. Excited to see how that does with consistency of the ammo. I will compare some of the loads done with a beam scale by hand against the numbers generated from the Chargemaster.

    I plan to do more shooting at 800-1000 yards in the coming weeks as well to see what kind of hit probability I can get with the heavy projectiles.

    Rich
     
    Re: Question on 208 Amax, RL17 - Update & New Question

    As an update I took 20 rounds with me to the range for some chrono work. These were loaded with my new Chargemaster 1500 which is great at consistently throwing powder charges. I full length sized the brass after cleaning, cleaned it again, trimmed it, chamfer/deburred, then set final neck tension with a neck sizing die. Both sizing dies were Redding Type S bushing dies.

    I had high hopes for this load of ammo and I loaded half with BR2s and half with CCI200s. I saw no difference in accuracy between the primers. The chrono results were disappointing. My SDs were in the teens and ES were quite a bit worse. I will update with the numbers when I get home from work and pull them off the Chrono but it was pretty big. This is the identical powder charge I was able to squeeze 9fps SDs out of earlier.

    My final conclusion on this load is that the powder, while producing excellent velocities, is just too finicky with temperature for my tastes. I had rounds that i really had to pull hard on the bolt to get it out of the chamber, but with no other obvious pressure signs. I would have rounds shooting in the low 2600s and then rounds that were cooking at near 2650fps.

    The powder is just too sensitive to be able to tune a load and expect it to maintain. Temp difference was only around 20F at most from the last chrono session.

    I will be starting a new thread to log results of the 208 Amax using Varget for the propellant. I will be shooting for 2500fps but may have to settle for less. The nice thing about the 208s is their BC. If you run the numbers, even at a modest 2400fps at sea level they are still supersonic beyond 1200 yards. With these rounds they don't have to be hurled at super fast velocities to be effective.

    For me, I value the accuracy over the speed. Doesn't take much difference in launch velocity to produce a sizeable difference in POI at 800-1000 yards. Living in Colorado the temperature sensitivity is a problem for me. In the fall and winter here it can be in the 20s and 30s over night and in early morning and up to 60+ by mid afternoon. Potentially at a match starting in the morning your POI could have a significant shift with RL17 just from the temperature change. To say nothing of the atrocious SD/ES numbers that don't lend themselves to good accuracy.

    Stay tuned I will see how Varget does and then re-assess.

    Rich