seating depth question for the pros

J

jwoolf

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Feb 2, 2010
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Dallas, TX
#1
Ok, I'm new to reloading for precision bolt guns but, I'm not new to reloading.

I've just bought the redding s comp neck dies. So, my question is, I'm loading for a 300wm for a LW 1:10 twist 26" barrel on an A3 stock bedded etc. etc.

I'm just starting to work up a load for it... only been out once with it.

I started by working the comp seating die with a pen on the bullet till I saw the bullet kissing the lands and found the right pressures.

My question is... I'm loading 220gr SMK ( haven't got any amax's or berger's yet )

Best practices with this bullet? Should I be shoving them into the lands or does this bullet need to jump a bit to get the best accuracy or, is this a dumb question and it varies from rifle to rifle?
 
#2
Re: seating depth question for the pros

just additional info... the gun seems to shoot like crap at 74gr of H1000 but, the groups tightened up around 74.5gr but, I was only mostly checking pressure on the first outing.

So, should I be seating off the lands some and starting over or does the SMK 220 shoot better in the lands a bit?

Got a bunch of groups shooting all through one hole at 74.5 and 75.0gr of H1000 but, I didn't have a crono because I didn't pick it up from my friend's house but, I didn't load for anything but figuring out pressures first outing.... watching brass and primers etc.

LOL, If I change the seating depth, I'll have to do the pressure thing again anyway and, I should have had the crono in the first place. Arrrg!



 
#3
Re: seating depth question for the pros

fwiw.....I have always heard and/or been told that each gun has their own likes and dislikes, so, its kinda a trial and error game. I've got a gun that i have been playing with and in the preliminary load development stages, the thing shoots really great and am kinda scared to keep changing things because it does so well. I am sure this hasn't helped you a bit, just saying....there may not be a "magic" answer that anyone can give you, only ballpark ideas.
 
#4
Re: seating depth question for the pros

Here's my first outing groups. Wind was blowing and, the break was getting loose and, I didn't notice that at first so, I feel like I have NO good data yet. ( 10mph wind )

I've locked down the brake now and, that won't come loose again. With a loose brake, you can't have any good data.

I printed a few groups that were... ok, I guess but, this was the first outing with the rifle and, if I can save some time with some of the more experienced folks here, I may be able to save some money and time if you guys have experience with seating depths etc. etc.

I'll figure it out either way, may just cost a shit ton of money to do it if I have to make all the mistakes myself. haha

IMG_1477.jpg
 
#5
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wards75</div><div class="ubbcode-body">fwiw.....I have always heard and/or been told that each gun has their own likes and dislikes, so, its kinda a trial and error game. I've got a gun that i have been playing with and in the preliminary load development stages, the thing shoots really great and am kinda scared to keep changing things because it does so well. I am sure this hasn't helped you a bit, just saying....there may not be a "magic" answer that anyone can give you, only ballpark ideas. </div></div>

Thanks for the reply, Sir.

I am starting from scratch here. It's not shooting badly by any stretch but, I'm wanting to get the most out of this thing.
 
#6
Re: seating depth question for the pros

One load I have used that was pretty accurate with that bullet is 49.0 of IMR 4320, Win mag primer and Hornady brass. Depending on the reamer used you might have good luck using the standard length of 3.340" If you want to hand feed as a single shot, you can run it on out. But you need to make a dummy round to see where the bullet hits the lands. As you get closer to the lands, especially if it touches, you will get a pressure spike. Watch for high pressure signs and take appropriate precautions.
 
#7
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body">One load I have used that was pretty accurate with that bullet is 49.0 of IMR 4320, Win mag primer and Hornady brass. Depending on the reamer used you might have good luck using the standard length of 3.340" If you want to hand feed as a single shot, you can run it on out. But you need to make a dummy round to see where the bullet hits the lands. As you get closer to the lands, especially if it touches, you will get a pressure spike. Watch for high pressure signs and take appropriate precautions. </div></div>

Yessir, that's kind of what happened. I was shooting for seating it in the lands. I used a bluing pen on the bullet and worked the comp seating die until I saw a very sharp ring on the bullet. The OAL on the bullets were around 3.496 to 3.50 or so. I started with LOW charge weights and got pressure signs at 76.0gr of H1000. That's about 2gr light of where the max load should have been for that bullet but, I was careful.

I'm just wondering if I should seat the bullet a few thousanths off the lands and, if that would help or not.

The answer is probably... go try it, dumbass but, I'm about to go and stretch this rifle's legs a bit on Saturday and, I don't have sufficient time to work up a good load before then... I may have time for one more 100yd session before this pig goes to the 1000yd range on Saturday.
 
#8
Re: seating depth question for the pros

them groups look nice to me, like the results from the rifle i spoke of in above post on a straight up, stock Remy 260 (justa glorified deer killer) I need to get some pics compressed so i can post em....but am lazy...

looks nice though jwoolf
 
#9
Re: seating depth question for the pros

LOL, I ordered 250 pieces of new win brass from powder valley because the new brass wasn't that much more than the once fired stuff you can find.... stuff arrived all bent to shit... there wasn't a straight neck on any of it and some of the cases have dented bodies etc. etc.... I just ran it through the neck sizing die to at least get the necks straight before I loaded it.... arrrg.

I'm so new with this rifle that, the data I got from Sat. wasn't even good data with the brake coming unscrewed a little a coupel of times when I didn't notice....

Feel like I"m back to square one and, I've got a range date on Saturday. LOL

I think I may seat a couple of thousanths deeper till I get the bullet off the lands by a couple of thousanths and test pressues and groups again ONE more time before Saturday and see what this thing will do.
 
#11
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wards75</div><div class="ubbcode-body">I'd say you are on the right path considering all the hicups....tight break and no wind.....oughta be pretty!!
</div></div>

Thank you, Sir.

Hell, I may just load a bunch for Saturday and go with what I got for now. ( but, I may not be able to help myself ) lol

I think I have to load some between 74.5 and 75.5 in .2gr increments with everything tight and see what happens before Saturday.

May not want to change two things before this weekend when I only have the opportunity to load once between now and then.

Arrrrg! I hate not knowing what I've got yet!!!!!

Then, with whatever I find, I'll have to load a bunch of those before Sat. morning. ( I'll bring a chrono too this time so, I'll at least have some dope for the rifle )

 
#12
Re: seating depth question for the pros

There are methods to developed loads; one is the OPTIMAL CHARGE WEIGHT method http://optimalchargeweight.embarqspace.com/ which IMO is the best. After you find the common POI point of impact and the optimum charge weight, you then will tune the OCW load by ajusting the seating depht.

Might seem a little confusing a first but it real is simple and fast. In about 20 rnds you will learn allot read and study the information from the link then do a search here, there are several threads. If you decide to use this method do it like it is written until you have a couple of years loading under you belt.

http://practicalrifler.6.forumer.com/ Is a web site that people who use this method post to to exchange information, you can post if you need help with results of you test. Its back to the old thing you have to do the work to understand the process. If you just select loads from other peoples work you will miss an oppertunity to learn a lot.
 
#14
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body">There are methods to developed loads; one is the OPTIMAL CHARGE WEIGHT method http://optimalchargeweight.embarqspace.com/ which IMO is the best. After you find the common POI point of impact and the optimum charge weight, you then will tune the OCW load by ajusting the seating depht.

Might seem a little confusing a first but it real is simple and fast. In about 20 rnds you will learn allot read and study the information from the link then do a search here, there are several threads. If you decide to use this method do it like it is written until you have a couple of years loading under you belt.

http://practicalrifler.6.forumer.com/ Is a web site that people who use this method post to to exchange information, you can post if you need help with results of you test. Its back to the old thing you have to do the work to understand the process. If you just select loads from other peoples work you will miss an oppertunity to learn a lot. </div></div>

WOW, that data is awesome!!!!! I'm reading away and, I can't stop... I'm a sponge.... I have one outing so, I may be able to do part of this before Saturday ( not seating depths yet ) and still have time to reload a bunch for Saturday. I'll back off the seating depth I'm currently using for the testing too.

got a lot of reloading under the belt but, just not this kind of loading...
smile.gif
smile.gif
 
#16
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body">Run with the OCW but this is a companion paper, this might hurt a bit but since you are a Eng. bon appetit.

http://www.the-long-family.com/OBT_paper.htm
Shock Wave Theory – Rifle Internal Ballistics, Longitudinal Shock Waves, and Shot Dispersion

http://www.shootingsoftware.com/pressure.htm note OBT Optimum Barrel Time markers

</div></div>

Great stuff! Thank you again!!!
 
#17
Re: seating depth question for the pros

Well, I took her out yesterday and printed a bunch of groups in .3gr increments. ( I had a crono this time )

I'm loading all new win brass and, this stuff is bent to hell and back. None of the velocities are consistent. I trickle charged each case and I neck sized everything. I found the sweet spot where the bullets are going all through one hole but, I'm afraid this brass has to be worked a LOT more than I did for the groups to get the consistent velocity I'm looking for out of the loads.

I mean, it's printing ok groups but, watching the crono and the bullets on paper, it correlates exactly so, I know I've got a rifle that is completely capable of great things. I just have to get the brass consistent ... probably would have worked better had I bought once fired.... that way I'd have fussed over the brass a lot more before loading anything.

I mean I have to CRUNCH this stuff through the expander ball to get the necks sized... that's GOT to be doing bad stuff to the brass before I load it and, it's showing on paper.

Now, all that said, the rifle is shooting this junk pretty well and when I can hit the velocity of the sweet spot, they all go through the same hole... every time.

It's a pretty good load but, maybe two in 10 rounds do something unexpected in velocity.... the other eight are going through one hole and the powder charges vary.... for example, I have some loads loaded .3gr more shooting the same velocity as a round loaded .3gr less.... I trickle charged every one of these rounds and fussed over the part I did and, I'm used to seeing my .308 rounds within 10fps or so for most rounds.... this stuff was going as much as 40fps different on the same load.

guess i learned a valuable lesson here with the new brass.... I've never loaded new brass before.
 
#18
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jwoolf</div><div class="ubbcode-body">I'm loading all new win brass and, this stuff is bent to hell and back. None of the velocities are consistent. I trickle charged each case and I neck sized everything. I found the sweet spot where the bullets are going all through one hole but, I'm afraid this brass has to be worked a LOT more than I did for the groups to get the consistent velocity I'm looking for out of the loads.

I mean, it's printing ok groups but, watching the crono and the bullets on paper, it correlates exactly so, I know I've got a rifle that is completely capable of great things. I just have to get the brass consistent ... probably would have worked better had I bought once fired.... that way I'd have fussed over the brass a lot more before loading anything.

I mean I have to CRUNCH this stuff through the expander ball to get the necks sized... that's GOT to be doing bad stuff to the brass before I load it and, it's showing on paper.

. . .

guess i learned a valuable lesson here with the new brass.... I've never loaded new brass before. </div></div>

Lesson #1:

Use Lapua brass. Of the multiple 100 case boxes I have used, only 1 case had to be set aside because of a bent neck (or any other problem I might add). No processing is necessary with virgin Lapua brass. Some will do it anyways, but it isn't necessary.

Prime
Charge
Seat
Shoot
 
#20
Re: seating depth question for the pros

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jwoolf</div><div class="ubbcode-body">I looked for Lapua 300wm brass but, I didn't see any. Is it available and did I just not find it? </div></div>

Whoops!

You're right. Lapua doesn't make 300WM brass.

EDIT: I can't <span style="font-style: italic">find</span> Lapua 300WM brass, but according to their reloading manual, they do make it (unless they made 1-off 300WM brass for their reloading data which seems highly unlikely).
 
#22
Re: seating depth question for the pros

Don't bother, at the unit cost and average life span of the .300wm brass you are probably better off just buying bulk rem or win and sorting by weight...
 
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