# Question about grain weight and twist



## budgetprepp-n (Apr 7, 2013)

Hi
Hey if you buy the scope I'm looking at you get a free turret marked for the bullet you tell them. I have an AR 16" with a 1-7 twist. So I was thinking that a 62gn might a good place to start. With a 1 in 7 that bullet is wound up good. You use a heaver bullet with a barrel that spins them fast.,, Right? 

I'm going to take my AR out and see what it likes. But I got to start somewhere.


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## SOCOM42 (Nov 9, 2012)

Answer is yes. My sniper rifles have 1-10 barrels for 178-180 grain match ammo, they are all 30 cal.

On the 5.56, 1-7 twist, is for 62 grain and up.

I use 1-9 because I have vast quantities of 55 grain ammo and a goodly amount of 62 grain, it is a compromise.

Some use 1-8 twist.

At the anticipated engagement ranges here the twist difference is academic.

The 55 grain bullet out of a 1-10 or 1-12 causes terrific wound channels from an unstable bullet.

My SP1 Colt which is a safe queen today has 1-12, was made in 1964 and I got it new back then.

I hit a chuck with it, literally blew the thing apart, like the 220 swift I use to use on them.


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## dwight55 (Nov 9, 2012)

budgetprepp-n said:


> Hi
> Hey if you buy the scope I'm looking at you get a free turret marked for the bullet you tell them. I have an AR 16" with a 1-7 twist. So I was thinking that a 62gn might a good place to start. With a 1 in 7 that bullet is wound up good. You use a heaver bullet with a barrel that spins them fast.,, Right?
> 
> I'm going to take my AR out and see what it likes. But I got to start somewhere.


Not a lot of reading, . . . but this will get you started down the right track:

How to Pair Barrel Twist Rates with Bullets - Guns & Ammo

My 1 in 7, 26 inch stainless barrel, . . . puts 15 out of 15 in a 2 inch by 2 inch sqare at 100 yds, . . . using a 40+ yr old Tasco scope I probably paid $15.95 for back then. And that is just plain old FMJ, . . . milsurp fodder.

May God bless,
Dwight


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## Smitty901 (Nov 16, 2012)

With an AR it is about doing more than one thing well and less about doing one thing perfect. 1-7 , 1-8 , 1-9 . Not to even get in to the 20 inch 1-12 and 1-14.
1-7 with 62 grain will cover a lot of needs well. It will kill , it will give you good range and if you can shoot good enough MOA for what the weapon is designed for.
My most accurate Ar is a 16.5 1 in 9. If just putting holes in paper at longer ranges .223 55 gr. But the 5.56 62 has a better kill and will come pretty close in punching holes.
I yet to find a real reason to use 77gr. We used them some times in the Army but it just did not make that much a difference. For many years issue has been 62gr 5.56.
I am going to be real interested in seeing what these two 18 inch ones do at longer ranges. Put 3 rounds in paper on a 25 meter zero the results are interesting. 
But not enough to make any predictions.


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## LunaticFringeInc (Nov 20, 2012)

In 5.56 with a 1 in 9 twist rate I get exceptional results in bullets from as light as 53 grs with some brands of bullets all the way up to Sierra 69gr Match Kings. Beyond that or less than that weight wise I start to have issues with bullets key holing in flight. I use a lot of 55 gr FMJ's, 64gr Power Points and 69 gr Match Kings.


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## Chipper (Dec 22, 2012)

Been loading some Nosler 69 grain BTHP,s that seem to shoot great out of all the rifles so far. The Savage Recon "really" likes them.


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