1-8 twist 16" .308 barrel

[generalzip]

I've done some ladder testing with my dta .308 with 175 smk using once fired federal brass and used varget powder with cci br2 primers. I then tried some 44.5 grain loads loading all the way out to a col of 2.847 but still can't get groups better than .9-1" on average. I have blown through probably 130 rounds including some fgmm 175 grain to compare to and at this point I think my bullet or bullet/powder combo needs to change. This short fast barrel is a new animal for me. I have some 240 grain smk laying around but feel that is too heavy. I'd imagine the fast twist would favor heavier bullets. Does anyone out there have any loads they think could give me a good shot? Particularly using the brass and powder I have on hand? I also have some ramshot tac. I was thinking of buying 190 gr smk, 208 gr amax and 185 gr Bergers. The Bergers are impossible to find right now though.

Just throwing this out there to get some ideas


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[Xtremegunnr]

First off...great little barrel. I ran 175 grainers at 2.815" with 43 grains of rl15. Pretty much the M118 LR. My accuracy load for long range was the hornady 225, 10 thousandths off the lands with 45.5 grains of reloader 17 and federal 210m primers. I think it was at 2400 fps or so. Shot great at 1000. Not .5 moa but not bad.

 

[Xtremegunnr]

The heavy bullets are going to get you the results. The light ones just dont go fast enough and dont have a good enough bc. The 208 would be good. I dont know about the 240. They have a lot of baring surface. Havent had best luck.

 

[generalzip]

The heavy bullets are going to get you the results. The light ones just dont go fast enough and dont have a good enough bc. The 208 would be good. I dont know about the 240. They have a lot of baring surface. Havent had best luck.

Yea I was saving the 240's for a .300 conversion and some .308 subs I plan on loading up. I'll try to get some heavier bullets to try


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[generalzip]

Anyone else have any ideas on powders or bullets to use in this short fast barrel?

I scrounged the internet for what little components are available and had limited luck but managed to pick up 100 each of:

178 grain amax
185 grain Berger match vld
208 grain hornady bthp

I'm looking all over for 190 or 200 grain smk but can't find any anywhere. I'll be using varget and possibly ramshot tac for these loads and will load the vld out to the lands -.01 and + .01. Any other suggestions are appreciated as I'm quite the newb when it comes to reloading. Especially with a barrel as unique as this. Would have been easier if the 175 smk worked as now I have 400 of them lying around with no use... :/


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[BCP]

Well with a 16" 1:10 -

44.5 varget in federal brass is a smoking hot load with a 175smk

Drop it down to 43 and then 2.8" for overall length and try again. With tac try 40.5.

For 208s I didn't have luck with tac or varget. 2000MR was better. I really think you need RL17 for that bullet to perform in 308 case.

With 185 lapuas I had great luck using 41.5 and 42.2 varget in LC brass @ 2.82. The Bergers might be similar. I've also heard of a 44gr load @ 2.9" with a berger 185 but that seems like an extreme.

AMAXs didn't shoot for shit out of any of my rifles until I seated them deep. Don't know why but as soon as I made them 2.78" they all shot great.

Probably have your best luck with lighter loads and just be happy that you have a compact, accurate rifle rather than hot rodding a 16" to get to the epic 1000 yards....

 

[generalzip]

I tried 43 gr varget at 2.805" and still no luck with the 175 smk. I might try to load out to 2.78" and 2.9" as an extreme measure just to try. Thanks for the note on the amax. I'll be sure to load some a bit shorter.

On a side note I threw some brass in the oven to dry after sonicating and forgot about it. It was probably in the over for a half hour max at 350f. The brass turned an oil slick color. I guess I kind of annealed the entire cartridge. Is this going to hurt anything? The neck tension still seems to be fine on them


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[generalzip]

Probably have your best luck with lighter loads and just be happy that you have a compact, accurate rifle rather than hot rodding a 16" to get to the epic 1000 yards....

I agree completely. I would much rather have an accurate load than one that reaches to 1000 yards. This gun will be for 600 and in. A .300 win mag conversion is on the way for 1000+ yard shooting. I'll also be loading some .308 subs if anyone has recommendations for that as well. I have 150 240 grain smk that I plan on using for that


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[BLDTYLRY]

On a side note I threw some brass in the oven to dry after sonicating and forgot about it. It was probably in the over for a half hour max at 350f. The brass turned an oil slick color. I guess I kind of annealed the entire cartridge. Is this going to hurt anything? The neck tension still seems to be fine on them

Personally I would not use them as my health is worth more than a few brass cases.

Have you thought about running an OCW Test. I finished a AR 308 20" two weeks ago and found out my accuracy load was 2grs below max and the best seating depth was 2.800". Shot a 3/4" 5-shot group at 100yds. Would have been 1/2" if it weren't for one of the shots. Re-shot the accuracy load a week ago and it's dead on. shoots consistent 5-shot 1/2" to 3/4" groups. Ladder Tests are great if you are a consistent shooter and have access to 300yds or more. OCW can be ran at 100yds but take a lot of time. I do a 5-shot OCW as opposed to the prescribed 3-shot OCW.

My DTA Covert A1 arrives Thursday and I'll let you know once I OCW the 168gr A-Max with Alliant 2000MR. I also have 178 A-Max on hand but I'm going to wait to see how the 168gr does first. Will also be OCW'ing 220gr SMK for subsonics.

Bo

 

[generalzip]

Personally I would not use them as my health is worth more than a few brass cases.

Have you thought about running an OCW Test. I finished a AR 308 20" two weeks ago and found out my accuracy load was 2grs below max and the best seating depth was 2.800". Shot a 3/4" 5-shot group at 100yds. Would have been 1/2" if it weren't for one of the shots. Re-shot the accuracy load a week ago and it's dead on. shoots consistent 5-shot 1/2" to 3/4" groups. Ladder Tests are great if you are a consistent shooter and have access to 300yds or more. OCW can be ran at 100yds but take a lot of time. I do a 5-shot OCW as opposed to the prescribed 3-shot OCW.

My DTA Covert A1 arrives Thursday and I'll let you know once I OCW the 168gr A-Max with Alliant 2000MR. I also have 178 A-Max on hand but I'm going to wait to see how the 168gr does first. Will also be OCW'ing 220gr SMK for subsonics.

Bo

Looking forward to hearing your range report.

About the cases. 350f is not very hot. Case mouths are annealed at 600f. I'm not worried about them blowing up or anything. Only thing I'd be worried about is a case getting stuck and ripping a head stamp off but I've never had a case get stuck in my bolt guns so not too worried about that. Has anyone else dried cases off in the oven? Haha


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[BLDTYLRY]

I shot the 178gr Amax's first then got comfortable and shot the 168gr Amax's. I kept the zero from the 178's; it's weird how the 168's shot high and right. Didn't get any chrono numbers because mounting the MagnetoSpeed was difficult while trying to use a bipod or sandbag. I plan to re-shoot the 178's because I think I can do much better.

178gr Amax

168gr Amax

 

[generalzip]

Interesting. Thanks for the pics and info. And yea I'm sure the 178 would have done better if you shot them better. I always practice dry firing and then fire off about 5 rounds of practice ammo before I shoot for groups to get the flinch out


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[BLDTYLRY]

The 178 OCW is usable but I want to see if I can shoot it better. I'm use to shooting with two-stage triggers; I'll have to look at the trigger assembly to see if I can mod it by lightening the creep/"1st stage" so I can get a more positive feel of the 2nd stage. My monopod arrives Friday so that should help with consistency.

On another note, when firing the 16" barrel I noticed some unburnt powder leaving the barrel. This makes me want to try a faster powder, thoughts? I've got 8lbs of 8208XBR which Hodgdon's reloading website says I can load 39.0gr to 42.5gr with the 175/178's.

 

[generalzip]

Not sure about the faster powders. Seems like a good idea to get more velocity but It may also have a negative effect on accuracy. I'll be loading up some 175 smk light loads, 178 amax, 185 Bergers, and 208 bthp and see how those all perform with varget. I also have tac on hand but want to try to work something up with the varget first as I'm low on br-2 primers. The components shortage is seriously killing me.


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[Rprecision]

Two things come to mind,

1. twist is measured by length of bullet, not just weight. What if you tried a 155 lupua (long higher BC) with a faster powder to get you MV up

2. I would be inclined to try 190 SMK. It will probably favor a faster twist but is light enough to get you a useable MV for extended range.

Interesting project, FWIW I have never had a faster twist then 1/10

 

[generalzip]

Just loaded 9 rounds of the following for testing (3,3 shot groups)

175 smk factory seconds
42 grains varget
Coal 2.81
Fgmm brass neck sized
Br2 primer

178 Amax
43 grains varget
Coal 2.81
Fgmm brass neck sized
Br2 primer

185 Berger match vld
42 grains varget
Coal 2.90
Fgmm brass neck sized
Br2 primer

208 hornady bthp
Coal 2.85 (3 rounds) 2.90 6 rounds
40 grains varget
Fgmm brass neck sized
Br2 primer

They will all fly this Saturday morning out of my 16" dta. I'll post pics when I get back


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[Dacam]

I think FGMM is not the best imho.
On a side note, there is a person selling 185 Berger OTM Juggernauts in the for sale section. A little on the high side in price but as you know they are impossible to find now.
I bought 2 boxes to try out.

 

[BLDTYLRY]

Generalzip

What's you methodology for your loads? How did you come up with 42grs of Varget for the 175 SMK at 2.81? 44.5grs at 2.847 seems hot but to adjust powder and COL at the same time seems like a lot of jumping around. Maybe you're doing stuff behind the scenes we're not seeing; just trying to understand.

My OCW points me towards loading the 178's at 47.7grs of 2000MR and adjust COL from 2.800 and increment/decrement 0.010; so I'll load 3rds of each: 2.790, 2.800, 2.810, 2.820, 2.830. I have my max length written down somewhere,

Bo

 

[generalzip]

I think FGMM is not the best imho.
On a side note, there is a person selling 185 Berger OTM Juggernauts in the for sale section. A little on the high side in price but as you know they are impossible to find now.
I bought 2 boxes to try out.

I bought 3 as well


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[generalzip]

1-8 twist 16" .308 barrel

Generalzip

What's you methodology for your loads? How did you come up with 42grs of Varget for the 175 SMK at 2.81? 44.5grs at 2.847 seems hot but to adjust powder and COL at the same time seems like a lot of jumping around. Maybe you're doing stuff behind the scenes we're not seeing; just trying to understand.

My OCW points me towards loading the 178's at 47.7grs of 2000MR and adjust COL from 2.800 and increment/decrement 0.010; so I'll load 3rds of each: 2.790, 2.800, 2.810, 2.820, 2.830. I have my max length written down somewhere,

Bo

I shot a LOT of 175 smk at various col at 43 grains and up so I wanted to see if dropping to 42 would improved accuracy. I'm not going for speed I'd rather have accuracy. Hopefully I can find something that will give me both. For the other loads I wanted to load at start or one grain above start according to the sheet that came with my lee dies. Again going for accuracy here and if they do well ill increase powder until accuracy diminishes. As for the various coal, Vlds I've heard to load at or just before the lands. I found my lands start at around 2.90. So I loaded some there and some with a little jump (.05). I plan to test more and hotter loads but am waiting for some more components I'm getting today to load more. Also getting some imr 4064 I'm gonna try


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[BLDTYLRY]

I normally work up charges first then play with COL. Here's an example of load testing I did on my AR 308 shooting 168gr A-Max and AR-Comp. I found an accuracy node at 41.2gr and started working on seating depth. At 2.168" measured to the Ogive I got my best grouping and best SD/ES numbers.

First round on each was off to the left so I adjusted the scope and shot the remaining 4-shots for grouping.

 

[generalzip]

I normally work up charges first then play with COL. Here's an example of load testing I did on my AR 308 shooting 168gr A-Max and AR-Comp. I found an accuracy node at 41.2gr and started working on seating depth. At 2.168" measured to the Ogive I got my best grouping and best SD/ES numbers.

First round on each was off to the left so I adjusted the scope and shot the remaining 4-shots for grouping.

View attachment 18906

What powder were you using for this? If varget 41.2 grains seems pretty low


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[BLDTYLRY]

RIF: AR-Comp.

42.8gr was getting light ejector marks so I backed down to the next accuracy node of 41.2gr. I could probably determine the best load without even looking at the groups just by the ES/SD numbers. Hence a chrono is very important when load developing.

 

[CK_32]

Wait OP so are you saying you've tried your loads and Factory FGMM and still can't get below 1"?

Or with the FGMM you can get below that?

If your not getting lower that 1" groups with match ammo maybe your rifle or perhaps you aren't capable of shooting below that yet?

Have a experienced good shooter try a few groups and see if he/she can shrink them to where you want. If he can then it targets your loads and your gun is one of the few that done like FGMM.

If they can't do it either then your rifle probably isn't capable of those typed of groups.

Even try a ransom rest if you have access to one.

GL and happy hunting. I'm still trying to hunt down my perfect load. So I feel your pain haha

 

[generalzip]

Wait OP so are you saying you've tried your loads and Factory FGMM and still can't get below 1"?

Or with the FGMM you can get below that?

If your not getting lower that 1" groups with match ammo maybe your rifle or perhaps you aren't capable of shooting below that yet?

Have a experienced good shooter try a few groups and see if he/she can shrink them to where you want. If he can then it targets your loads and your gun is one of the few that done like FGMM.

If they can't do it either then your rifle probably isn't capable of those typed of groups.

Even try a ransom rest if you have access to one.

GL and happy hunting. I'm still trying to hunt down my perfect load. So I feel your pain haha

Fgmm and my first set of hand loads (which mimick fgmm. 175 smk and same brass) can only get to about .5-1 moa. If this was a stock Remington I might be happy with that. I had another r700 .308 I could put three rounds consistently below .6 moa honestly with some sub .4 moa with fgmm. I was recently out with a buddy and put 4 of his hand load .338 lapua magnums through a savage into .82" at 300 yards.

Would blaming my abilities make me happy? Yea. However I have shot much much better than the groups I'm seeing with this dta. My hopes are just that the 175 smk is not what it likes. That's why I'm trying all these different bullets.

I am by no means the best shot on the world but if this ammo/rifle combo was sub half minute my shooting would at least be able to show that after 10 3 round groups. It is a new gun so maybe I'm not used to it so I will have my buddy who is a great shot try it as well.

Thanks for all the suggestions guys. I'll be sure to report back with my findings. I'll be trying imr 4064 this weekend too


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[BLDTYLRY]

Generalzip

Not questioning your ability to shoot but more interested in your load development methodology. Every weapon and every barrel shoots differently hence the reasoning behind handloading but if you are "cloning" loads and not truly developing them from ground up; not sure how successful you can be. I spend about 50-rounds per bullet/powder/brass combination and can successfully find accuracy loads, never have I just taken someone else's load or try to shortcut the method and expect to achieve success. Sometimes shooting match factory ammo or someone else's or another weapons accuracy handload works out but that's just betting on luck and in an area of science and repeatability--I don't count on luck.

Just an observation
Bo

 

[gstaylorg]

I've shot many, many different factory loads in my Covert, ranging from 150 gr SSTs up to 190 gr SMKs, and quite a few in between. Most ranged between ~0.5 and ~0.8 MOA in my hands, at ranges from 100 to 600 yd. My feeling is that the ergonomics of the short bullpup design of the Covert require much more careful handling on the part of the driver than a Remy 700-type bolt gun in order to produce sub-0.5 MOA accuracy. For me personally, it's just more difficult to drive it as precisely as I can a more traditional bolt gun. That's not to say it can't be done, it just requires more from the shooter. So your issues may be due at some level to the design of the rifle itself, rather than solely the ammo.

 

[generalzip]

Generalzip

Not questioning your ability to shoot but more interested in your load development methodology. Every weapon and every barrel shoots differently hence the reasoning behind handloading but if you are "cloning" loads and not truly developing them from ground up; not sure how successful you can be. I spend about 50-rounds per bullet/powder/brass combination and can successfully find accuracy loads, never have I just taken someone else's load or try to shortcut the method and expect to achieve success. Sometimes shooting match factory ammo or someone else's or another weapons accuracy handload works out but that's just betting on luck and in an area of science and repeatability--I don't count on luck.

Just an observation
Bo

I understand and agree completely. You are right in that I'm trying to take a shortcut to save time and money. Basically I wanted to try different combinations somewhat randomly to get something that shot decent. Say half moa consistently. From there I would use that combination and vary the powder amount. Then once that was tuned vary the coal. I basically just wanted to "screen" through some components. I understand this May not be typical of even practical for reloading but it actually does have some statistical foundation. I've taken some experiment design and statistics classes, I just wish I still had the JMP software so I could design the ideal experiment and run it all.


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[generalzip]

I've shot many, many different factory loads in my Covert, ranging from 150 gr SSTs up to 190 gr SMKs, and quite a few in between. Most ranged between ~0.5 and ~0.8 MOA in my hands, at ranges from 100 to 600 yd. My feeling is that the ergonomics of the short bullpup design of the Covert require much more careful handling on the part of the driver than a Remy 700-type bolt gun in order to produce sub-0.5 MOA accuracy. For me personally, it's just more difficult to drive it as precisely as I can a more traditional bolt gun. That's not to say it can't be done, it just requires more from the shooter. So your issues may be due at some level to the design of the rifle itself, rather than solely the ammo.

I couldn't agree more. I do agree it is a VERY stubby feeling rifle and you don't get that smooth panning you get when an extra 2 lbs is hanging out in front of the bipod or bag. I used front and rear bags to reduce this although I feel the gun is actually more stable with a bipod and rear bag. At any rate I'll be sure to post my findings for you guys so you can see how this odd but possibly successful (lucky) experiment turns out.


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[BLDTYLRY]

I would recommend you look at QuckLoad and Optimum Barrel Time. My 178gr OCW load compared to QuickLoad and OBT happen to confirm the testing I do. Theoretically OBT makes sense but to be non-caliber specific and leaving out details like barrel twist seems flawed but so far in my testing OBT seems to work.

Do you have access to a chrono when you go to the range? If so, I can build you a OCW load sheet for you to try out.