AR Twist Rate?

[porscheboy]

Finished my lower last weekend, and now moving on to the upper, I know that I want a heavy (.920) barrel and either a 20" or 24" length. That said, I do not know what twist to get, 1 in 8 or 1 in 9? The rifle will be used for targets up to 200 yards. Suggestions for other options of barrel length and combinations would be great...

-Thanks in advance

 

[TylerPearce]

All depends on what bullet weights (length of bullet actually) you will use. If you want to go above 62 grains, get something tighter than 1:9.

 

[rcmodel]

1-9 is the most versatile all-around twist you can get.

It will shoot anything you can find on sale, from 45-50 grain varmint loads up to the 69 grain Sierra Match Kings.

rc

 

[XM855]

I have a 16" 1:9 right now and all the shots touch with 69gr MatchKings at 100 yards, but I always wanted to have the option of loading heavier bullets without worrying about stabilization issues.

If you're only shooting out to 200 then I don't know if you will really need to go up to really heavy/long bullets i.e. 75gr. But since you're talking about a 20-24" barrel then it looks like you're going for accuracy, so a 1:8 may be better suited.

As long as you don't plan to go shoot varmints or load bullets less than 55gr then 1:8 seems to be the way to go.

Just my thoughts.

 

[TexasRifleman]

If you plan on shooting any bullets over 70gr go with the 1:8, otherwise 1:9 probably gives you a wider selection of barrels.

 

[suzukisam]

can I make a suggestion? 1:7 WOA sdm 16" you can shoot anything from 55 gr up. I shoot 75 gr pills out of it. also the sdm barrel is a .920 with heavy fluting and the milled to a heavy barrel from the gas block forward. both my WOA ss bbls are capable of 1/2 moa. the thing is that as a general rule it is hard to over spin a light pill but it is very easy to under spin a heavy one. so your better off to go with a little faster twist than what you think rather than wish you could shoot the heavy long range bullets..

[/IMG]

 

[HOLY DIVER]

yep i depends on what bullet you are going to shoot if you don't hand load 69 and 77grain are hard to find on the self so i'd say a 1/9 would be the way 2 go but if u hand load get what ever twist u like. at 200yds a 52grain match king will give u awesome results

 

[supercalvin56]

I'm with Sukukisam! I have a 1:7 WOA 22" varmint upper on a RR lower. I can't find a reason to go with the slower twist. Mine easily shoots the 40, 50,52-53, 60 grainers as fast as I can push them without blowing up. They always shoot under 3/4". Plus, I can shoot the heavy 69 or 75 grainers if I want and everything in between. IMHO the 1:9 isn't the most versatile, 1:7 is. For the most part, I think that "overspinning" a bullet is a myth. It might happen but most of us will never see it.

 

[Jim Watson]

200 yards isn't far.
What is your target?
What is your typical shooting position?

Bear in mind that a benchrest shooter will be using a 14" twist and 52 grain bullets at that range. Things change when you get out to 600 yards, though.

 

[snakeman]

For target work, I would go for a 1 in 8 or 1 in 7 and use 55 gr. or heavier bullets up to 75 gr.

 

[porscheboy]

I plan on shooting paper and varmints with this barrel and would like to experiment with handloads as well. So I think 1-8 twist is the way to go.

 

[Birddog1911]

Keep in mind, that from an 18" to 20" barrel, you only gain about 20 FPS; I believe I once heard it is only 9 FPS. The rifle will be handier with the shorter barrel. Accuracy will not be affected, just velocity.

 

[sarduy]

i have a m4grey with a 1/7 and it's damn accurate with 55gr, i said go with 1/8 and you have the best of both world