bfm
NES Member
You have a 1 in 12 barrel?
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AR accuracy and ammo
- Thread starter Crotchrocket
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You have a 1 in 12 barrel?
xtry51
NES Member
chrbla2000
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According to this article, you should be using 62 or 77 grain for maximum accuracy with that twist rate:
http://blog.cheaperthandirt.com/ar-15-barrel-twist-explained/
-chris
http://blog.cheaperthandirt.com/ar-15-barrel-twist-explained/
-chris
mikelawtown
NES Member
MrGunsngear did a vid on some ammo out to 100 yards with a bunch of brands and Freedom Munitions did very very well. I'll have to check my cart on which it was.
bfm
NES Member
Understood. Outside of real specialty barrels you do not often see anything slower than 1 in 9 and given that assumed he mostly shot issued ammo I was surprised.
I honestly wish there were more 1 in 12 5.56 barrels out there as I mostly shoot 55gr 193.
xtry51
NES Member
I think you can grenade even heavy rounds if you push them too hard. Can any HP shooters confirm this?
I sometimes dabble in pushing .223 when I get a new powder, but I don't typically load crazy hot beyond more than 5-10 test rounds to see where I get primer cratering. Never had one pull apart on me.
I sometimes dabble in pushing .223 when I get a new powder, but I don't typically load crazy hot beyond more than 5-10 test rounds to see where I get primer cratering. Never had one pull apart on me.
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The accuracy conversation shouldn't be about ammo when the OP has an $80 chrome lined barrel he got off eBay. If he's getting 1MOA from FGGM he should be thrilled. Could handloads shoot better? Probably.
OP is "unsure" if a better barrel would be worth the money. What?
This makes no sense to me. Cart before the horse.
OP is "unsure" if a better barrel would be worth the money. What?
This makes no sense to me. Cart before the horse.
In trying to reach 1,000 yards with my AR, I pushed 90 grain pills pretty damn hard and never saw any grenades or keyholes. I'm fairly certain the brass or primer would fail before I was able to accomplish that.
I also must go +1 on the new barrel comments. Complaining about shot dispersion from an $80 eBAY bbl is rather absurd.
Get Blackhills in 55gr and 77gr. Shoot both from a bench, or better yet have someone you know who is a better shooter than you shoot 5 shots of each benched.
I'm guessing it is probably you, not the gun. Also may want to double check that barrel nut is actually tight
5MOA is ridiculous. Like smoothbore ridiculous.
ETA:
When you say 5MAO, are you talking about a 5" diameter group or a 10"?
A 4" diameter group is 2MOA, not 4MOA. It's the deviation from the center of the group, not the diameter. For reference the DOD standard for M193 is it must be sub 2MOA. So a 3.99" group at 100Y is acceptable.
![[shocked]](/xen/styles/default/xenforo/smilies.vb/007.gif "Shocked [shocked]")
they use a mean radius average for testing.... then drop the worst 4% or something like that.
Average mean radius is a good indicator of accuracy but a minute of angle is a minute of angle.
it matter not what the method each will show its face.
mean radius avarge is tough to say what it really means for MOA
you could have a 10 shot group that mean radius average is 1.3"
9 shots 1" from center and 1 shot 4" from center . for argument lets just say all 9 shots are in the same hole 1" from center and you have the 10th shot 4" from center thats a 3" difference center to center...now that really does not play well as you need to be measureing from the center of the group...
when you start to over think the math things get screwy. Pick a method that makes sense to you and works for you.
https://www.ar15.com/forums/t_3_16/512887_.html&page=1
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The DIY coper plated 62g homebrew ammo you always see me shooting can have the plateing stripped off if driven much past 3k fps.(my platings only .004-.005 thick) Its highly unlikely to be able to shed the jacket of a true jacketed projectile without the projectiles themselves being defective.
If you want to read the data for M193
Check out MIL-C-9963F that's the newest I know of from 1976. You can also try to find SCATP-5.56 for testing info. M193 was in testing for the 1/12 M16s
The standard was Average Mean Radii @ 200 yards to be a max of 2.0" this of course was shot from a accuracy testing device. If you think they benched a USGI M16 for the testing...no.
So that would be a 4" average group or roughly 2moa. Yet as stated this is a average. You could have some really good groups in the test and some really bad groups as long as the average is good it's good enough for GI. Also consider the groups where measured from the center of the group not the center of the target or even from the aiming point. They fired several thousand rounds with say 100 shots in each group and then averaged it all.
Check out MIL-C-9963F that's the newest I know of from 1976. You can also try to find SCATP-5.56 for testing info. M193 was in testing for the 1/12 M16s
The standard was Average Mean Radii @ 200 yards to be a max of 2.0" this of course was shot from a accuracy testing device. If you think they benched a USGI M16 for the testing...no.
So that would be a 4" average group or roughly 2moa. Yet as stated this is a average. You could have some really good groups in the test and some really bad groups as long as the average is good it's good enough for GI. Also consider the groups where measured from the center of the group not the center of the target or even from the aiming point. They fired several thousand rounds with say 100 shots in each group and then averaged it all.
Interesting.
This is important. When i started shooting i bought a few boxes of the reject stuff and it was awful. Like 8 MOA.
The surplus stuff is decent. You're not going to win any matches with it, but it's acceptable for practical accuracy.
usp45ct
NES Member
If you poke around long enough for these MIL documents you will find some crazy shit and see how "US "G"ood "I"nuff " is not always that good.
Used to have a gent at club who was a engineer at Quantico he would often bring in various Mil spec reports , manuals , and training manuals.
One that stood out was a bulletin to completely ignore the accuracy standards for the M14 as they just could not shoot well enough to hold any standard that US Army put out.
Weapons accuracy and Ammunition Accurracy are completely different. Also the difference between a newly issued weapon and a weapon,that went through the arsenal for rehab is different.
Have fun.
You want to add a little fun to your hunt for accuracy with cheap ammo and anything labeled M193/855 tear down 20 rounds or so of each. Weigh and inspect the powder and bullet from each cartridge. Look inspect it closely.
As far as any "surplus" 5.56 NATO. We are not getting any 5.56 surplus back from the U.S. Army.
We are either buying rejected lots of 5.56 NATO from the manufacture or over runs that where not inspected. These rejected lots can be failed for many things. Read the MIL document I listed before and they have a long list of items they test ammo for. Ammo can,fail for USGI for accuracy(m855 is worse than M193) how much force it takes to pull the bullet out of the neck, dings ,scratches , weight of bullet, powder charge, sealant and the list goes on.
So let's say the production lot is 100000 rounds.
They pull 1000 random cartridges and inspect them.
If they find X % failure for any of the items they are checking that lot is pulled. It could be for something like the sealant around the bullet is insufficient or the average velocity was below standards.?
I will tell you if you like shooting and have the time to actually go shooting vs me who has plenty of time but I'm at home 90% of the time. Do not waste your time with all this shit. Go shoot.
Buy some ammo to try and when you find the magic brand RUN as fast as you can and buy several thousand rounds of the same lot# if possible.
As far as I have found the targeting and accuracy test for USGI rifles has not changed much since WWII. 5 consecutive shots at 1000" with in 1.77" dia group.
Unfortunately I lost all this Crap on my old PC.
bfm
NES Member
Why? That is less than 30 yards.
This is how you end up with dwarfs towering over Stonehenge.
I have found Federal Gold Medal Match 69's to vary by lot. Same gun, .5 MOA vs. 1.25 MOA. It's OK if you have decent lots.
Try Norma Match 77's. The brass is outstanding for reloading as well.
Ditch the barrel for a WOA or better yet a Compass Lake. Along with the barrel, buy a new bolt that is headspaced to it. Follow break-in procedures. Shoot .3 to .5 MOA with the Norma Match.
If you want to consistently shoot below .3 MOA, approaching .25 MOA out of an AR, you will need to reload and be good at it.
Try Norma Match 77's. The brass is outstanding for reloading as well.
Ditch the barrel for a WOA or better yet a Compass Lake. Along with the barrel, buy a new bolt that is headspaced to it. Follow break-in procedures. Shoot .3 to .5 MOA with the Norma Match.
If you want to consistently shoot below .3 MOA, approaching .25 MOA out of an AR, you will need to reload and be good at it.
bfm
NES Member
From WOA FAQ.
HOW SHOULD I BREAK IN MY BARREL?
I suspect that more barrels have been damaged than helped by "breaking in". Barrel makers take a lot of care to get a uniform finish on the inside of a barrel. Barrels are lapped not so that they will be smooth, but so that the finish and dimensions will be uniform over the entire barrel. When you use an abrasive cleaning compound you will change the finish on the inside of the barrel. Since some areas of the barrel are going to be protected by copper that you are trying to remove, and others areas are not, the surface finish is no longer going to be uniform. Since I got a bore scope I have backed off on my use of abrasive bore cleaners. I use them, but not nearly as aggressively, particularly on a new barrel.
My personal break in procedure is to take a new upper to the range and zero the front sight and shoot a group or two. This will take about 15-20 rounds. I then bring it back to the shop and clean it good with shooters and a good quality brush. I check it with a bore scope, but generally very little copper fouling is present. Depending on how it looks I may hit the throat lightly with some JB. That's it, it is now broken in.
This is for all for good quality hand lapped barrels. I will get a little more aggressive with mass produced barrels.
For general cleaning and barrel maintenance we use Hoppes #9 for cleaning, Break Free CLP for lube, and only use Dewey rods.
I've witnessed rounds not making it to the target (grenading) a total of 2 times. The first time was over ten years ago, so I don't really remember what was being used and what was causing it. The second time was about a month ago. I was match director and was watching the shooter after numerous calls to pull his target only to find no visible hits. He was shooting 75 grain Hornadys, I think, out of an unknown 1-8 barrel. 20-30 yards out from his barrel there was a big "poof" where the bullet jacket came apart. Another shooter was scoring for him and watching the trace. He said it just made a big corkscrew and either hit the safety berm or went elsewhere. We took him off the line for safety reasons. It wasn't the bullet or barrel twists' fault: it was a sizable burr in the throat or near the throat that must have scored the jacket enough to strip it.
Thanks. This is something I can go out and test. A couple of packs of Norma Match 77gr should get me .5MOA (extreme spread). If it doesn't I should get a match barrel. If it does get .5MOA or better the money would be better spent on reloading equipment. The Compass Lake barrels/uppers are twice the price of the WOA, are they worth that much more?
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