Barrel Rate VS Grain Ammo

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Red Dawn

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I just picked up an AR 15. It has a 1/9 twist rate barrel in 5.56. I know it's not match so I know there's some ammo I won't get the best accuracy with. What's your formula you use for the barrel twist rate vs gr ammo you buy and do you stay with brass or do you buy steel. Cold beer and Free advice appreciated
 
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Dinky Dau

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I just picked up an AR 15. It has a 1/9 twist rate barrel in 5.56. I know it's not match so I know there's some ammo I won't get the best accuracy with. What's your formula you use for the barrel twist rate vs gr ammo you buy and do you stay with brass or do you buy steel. Cold beer and Free advice appreciated
Fast rate of twist will not stabilize a heavier bullet. 1/9 twist I don't go about 62 grain, with 1/7 I can go to 77 grain, the slower the twist the heavier bullet will stabilize..This has worked for me.
 

TattooedGunner

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Whatever you are wanting to shoot just buy a box of it and see what it does for you. I think the barrel twist/bullet weight thing is made out to be a much bigger deal than what it really is. Especially if you are just going to use your AR for plinking at 25-50 yards. Now, if you are wanting to shoot long range it would make more difference. Depends on what you are wanting to do with it.

I shoot steel case. I won't own a gun that won't shoot cheap ammo.
 

Red Dawn

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Fast rate of twist will not stabilize a heavier bullet. 1/9 twist I don't go about 62 grain, with 1/7 I can go to 77 grain, the slower the twist the heavier bullet will stabilize..This has worked for me.
The 55 - 62 is what I see a lot of on the shelves and I guess that should get me where I need to be then @Dinky Dau
 
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Dinky Dau

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Best way to find out is get out there and try it..I do a lot of distance shooting and reloading..This has worked for me..I'm sure others will offer their experiences also..That's what makes this site so good..You have a lot of shooters with, a plethora of information..Good Luck
 

Red Dawn

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So plinking steel cased is the way to go and let's say matches or distance shooting go to brass. Is there any long term problems from shooting a lot of steel cased that you see.
 
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TattooedGunner

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So plinking steel cased is the way to go and let's say matches or distance shooting go to brass. Is there any long term problems from shooting a lot of steel cased that you see.

Yes and no to both questions.

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/

That basically says that steel case does wear your barrel faster but you save enough money to buy a new barrel and still come out ahead.

Also, you will want to clean the gun after shooting steel case before going to brass or you will probably get stuck cases. What happens is the steel cases do not expand like brass cases do so they let more carbon/grit get back into the chamber. Then if you shoot brass case in that dirty chamber when it expands it gets stuck. Then you have to field strip the gun and jam a cleaning rod down the barrel to get the stuck case out.

For me, my AR is mostly a close range plinking toy so steel case does everything I need it to do. You will have to make that choice.
 

Laufen

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I just picked up an AR 15. It has a 1/9 twist rate barrel in 5.56. I know it's not match so I know there's some ammo I won't get the best accuracy with. What's your formula you use for the barrel twist rate vs gr ammo you buy and do you stay with brass or do you buy steel. Cold beer and Free advice appreciated
You'll be fine from 40-64 grains. My best shooting AR is a 1 in 9 twist barrel. It's ideal for 99% of the off the shelf ammo you'll find. If you want to shoot heavier match bullets a 1 in 7 will be necessary.
 

PewPewPewCo

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Whatever you are wanting to shoot just buy a box of it and see what it does for you. I think the barrel twist/bullet weight thing is made out to be a much bigger deal than what it really is. Especially if you are just going to use your AR for plinking at 25-50 yards. Now, if you are wanting to shoot long range it would make more difference. Depends on what you are wanting to do with it.

I shoot steel case. I won't own a gun that won't shoot cheap ammo.
It makes a massive difference when accuracy and projectile effectiveness matter
 

Laufen

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So plinking steel cased is the way to go and let's say matches or distance shooting go to brass. Is there any long term problems from shooting a lot of steel cased that you see.
I shoot all brass, hell you can buy poly tipped brass cased Federal for $6/20 from PSA right now. That's dirt cheap. Steel won't hurt over the short term, but there isnt' a big enough diffference in price to justify shooting it. I don't skimp on ammo, tires, motor oil, shoes or socks.
 

freedom

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So plinking steel cased is the way to go and let's say matches or distance shooting go to brass. Is there any long term problems from shooting a lot of steel cased that you see.

Steel cased isn't that bad on accuracy, you can do better but also worse with brass ammo. Steel is plenty good enough to shoot to appleseed standards, if that's what you're concerned about.

Everyone is basically right about twist rate, but it doesn't make that much difference. I doubt you could tell the difference in groups fired from a 1/7 and 1/9 twist using 55gr ammo.
 

EugenFJR

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The only reason the army uses 1/7 twist ammo is b/c it is needed to make sure the tracer ammo will "light up" and be stable at distance. A lot of shooters compete w/ 1/8 & 1/9 barrels... I have a 1/9 AR that likes the 69 grain stuff. The only way to find out what it likes, is to shoot a bunch of stuff and take notes.
 
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freedom

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Twist_VS_Grain.jpg

Not that what I do should matter to you, but the last two barrels I've purchased have been 1/8. I also have a colt with 1/7 and a DD with 1/9. 90% of what I shoot is 55gr. My "match" build shoots sub moa with 55gr reloads and about 1 moa with pmc bronze. I've tried to see a difference between the 1/7 and 1/9 in the past and couldn't tell a difference. Is possible it matters more at distance, but I've also made 700 yard shots with 55gr and a 1/7 twist.

To the extent it matters for accuracy, I doubt you or me shoot good enough to isolate the difference.

I have read it has a greater effect on terminal ballistics. That the 1:7 overstabilizes 55gr so it pencils through bad guys. The original twist rate of 1:12 caused the 55gr to tumble when it hit a bad guy making stops easier. But for paper or steel, I don't think it means much.
 

PewPewPewCo

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View attachment 6377

Not that what I do should matter to you, but the last two barrels I've purchased have been 1/8. I also have a colt with 1/7 and a DD with 1/9. 90% of what I shoot is 55gr. My "match" build shoots sub moa with 55gr reloads and about 1 moa with pmc bronze. I've tried to see a difference between the 1/7 and 1/9 in the past and couldn't tell a difference. Is possible it matters more at distance, but I've also made 700 yard shots with 55gr and a 1/7 twist.

To the extent it matters for accuracy, I doubt you or me shoot good enough to isolate the difference.

I have read it has a greater effect on terminal ballistics. That the 1:7 overstabilizes 55gr so it pencils through bad guys. The original twist rate of 1:12 caused the 55gr to tumble when it hit a bad guy making stops easier. But for paper or steel, I don't think it means much.
Yaw, not tumble.

Tumbling is for shitty would channels
 

TattooedGunner

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It makes a massive difference when accuracy and projectile effectiveness matter

Right, but out of everybody that shoots ARs, how many does that matter to? That's why I said it depends on what you are wanting to do.

Me personally, when I shoot ARs I'm just going out to the range, putting up some IDPA targets and running around a little bit and plinking. So neither of those really matter for that. At 25-50 yards Tula shoots plenty accurate enough for what I want to do. I also have better Ammo If I wanted to do something more serious with it.

If you are looking to buy ammo for long range use, then of course you need to match your twist/weight, and do a little more research. But as a general rule, you wouldn't use cheap crappy ammo for any serious or long range use.
 

PewPewPewCo

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Right, but out of everybody that shoots ARs, how many does that matter to? That's why I said it depends on what you are wanting to do.

Me personally, when I shoot ARs I'm just going out to the range, putting up some IDPA targets and running around a little bit and plinking. So neither of those really matter for that. At 25-50 yards Tula shoots plenty accurate enough for what I want to do. I also have better Ammo If I wanted to do something more serious with it.

If you are looking to buy ammo for long range use, then of course you need to match your twist/weight, and do a little more research. But as a general rule, you wouldn't use cheap crappy ammo for any serious or long range use.
If it's under 200yards I won't even bring the rifles out, he'll I probably won't even show up if it isn't some long distance stuff
 

boss_hawg

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like others have said, if you're not comp shooting at long range then it probably won't matter too much.

I use 1x7, x8, x9 and focus more on the barrel profiling, lining (or lack therefore), finishing, gas system length, and mfg reputation.