ar ammo question

[eldogg]

16 in. barrel with a 1/9 twist. what ammo for ranges 50m-250m? 55 or 62 gr., why?

[ken98k]

62 grn.
55 grn. bullets work best with a 1:12

[TheCol.U.S.M.C.]

I wouldn't try to shoot anything over 62gr. the 1 in 9 twist won't stablize the round but if your not shooting past 300yrds it might not be that big of a deal your group size may be a little big tho.

If you want to shoot loads over 62gr. you will need a faster twist barrel like a 1 in 8 or even better would be a 1 in 7 to get a tighter group

[dustoff_doc]

In general 1/12 = 55 and less, 1/9 = 50 - 70 and 1/7 = 60 - 80. I would test fire a bunch of different grain bullets. I have found the some guns like different stuff and don't follow the norm.

[RaccoonRough]

Originally Posted by ken98k

62 grn.
55 grn. bullets work best with a 1:12

+1 ditto.

But experiement on your own.

RR

[1biggun]

55 grn. bullets work best with a 1:12

HMMMMM I have a 1-9 twist on several rifles including bolt actions they all shoot 45 and 50 grain on up to 70 grain ( I havent tried heavier) over stabalizing a bullet is more of a problem if the bullet not good quality an nonconcentric. My most accurate load is a 50 gr in my 1-9 AK varmit build (sub 1/2 at 100) . at short ranges like out to 300 yards speed is your friend shoot the lighter rounds for a flatter trajectory. at long range the better BC of heaiver bullets is the trick. I use 50Gr on praire dogs out to 400 yards and the heaviey stuff for longer range. all the guys I shoot with shoot savage bolt actions in 1-9 and all of them shoot 45 or 50 grain out them with very good accuracy.

fast twist dosent nessacrly mean you got to shoot heavier bullets. take a .308 or 30-06 for example most are 1-10. most guys hunt deer with them and use a 150-165GR bullet. but the barrel is designed to stabalize a 210 GR. IMOO many .30 cals would be better served with a slower twist. why does a 7.62x39 need to be 1-10 APROX like most aks are??? 30BR shooters shoot much slower twists with 125 GR bullets. a 1-14 or even a 1-18 might be a better choice IMOO. I have 5 30-06,s that I hunt with I have never shot more than a 180 GR bullet out of any of them. so why do I need a 1-10 twist???? I dont but it allows manufacutres to sell a one size fits all. the fast twist causes more pressure and barrel wear over a slow twist. I wanted to build up a fast twist 22-250 but everything I read is it cuts the barrel life dramaticaly. the 223 gets away from it because its not loaded nearly as hot.

also with the 223 what you are shooting is also important. paper what ever is the most accurate. varmits like Praire dogs the lightest you can shoot and still be accurate at that range. Deer (I dont hunt deer with .22 cal) you want the big stuff and the proper bulllet. what are you shooting at??

[uhcoog1]

my 1-9 loves 69 grain... haven't tried anything less than 55 grain

[j427x]

i have a couple 1 in 9 inch twist that will shoot 75gr very well--

[pspeller]

I concur with 1biggun. I shoot a couple different AR rifles 1:7, a 1:9 and an ancient SP-1 with a 1:12. I personally have not experienced over stabilization with my faster twist rifles. Although I rarely shoot lighter than 50gr match bullets. My 1:9 likes the 69gr match with 24.7 gr of RL-15 behind it.
Commercial match ammo would be a good compromise if you don't roll your own. An alternative may be to try the IMI ammo available at Wideners. If this is anything like previously imported Israeli ammo it should be top notch. I'm sure some people remember Samson brand ammo. Shot like match.
Just my opinions YMMV.
ps

[Rich]

My 1:9 carbines shoot best with 52 gr Sierra Match Kings out to 300yds. 62 gr M855s shoot well also but 69 gr commercial bullets spread out to about 3 in at 100yds. But that's just my rifles. Each barrel seems to be kind of like a fingerprint - there will always be some differences from one barrel to the next. I used to have a 1:7 carbine that would rip the jackets off commercial bullets. May just have to experiment a little.... Trying different loads always makes for an interesting day at the range. Have fun!