6X45 Barrel Twist???

LukeW

New member
If this has been hashed before, I'm sorry...I am seriously considering a 6X45 build for yotes. I am looking for some help with barrel selection. The handful I have seen are either 9 or 10 twist barrels. I intend to shoot a 65 or 75 gn bullet. My question is will these bullets shoot well in fast twist barrels. Does anybody make a slower twist barrel? Anyone's first hand experience would be appreciated.
 
I'd opt for 9. My understanding is Black Hole is using that as their standard.

It should handle the lighter bullets fine and will let you go up probably as high as 90ish (if you can get them to fit).
 
I have a 1:12 twist Dtech 22" upper in 6x45. I have only run 60 and 70 grain bullets through it. Both weights key hole at 100 yards. Shooting a heavier bullet in an AR didn't appeal to me with mag length restricting my OAL thus limiting powder capacity which sacrifices velocity.

Just my own thoughts. I really should try some heavier bullets.
 
I have used 1/10 and 1/12 and 1/14 all with good results. I have never shot any heavier than 80gr bullets though. My 1/14 shoots 75gr Hornady HP 's and VMax's both with great accuracy. With that being said my older 1/10 twist DTech with the Shilen barrel was/is as accurate as any gun I have ever shot.
 
Originally Posted By: BBsteelI have a 1:12 twist Dtech 22" upper in 6x45. I have only run 60 and 70 grain bullets through it. Both weights key hole at 100 yards. Shooting a heavier bullet in an AR didn't appeal to me with mag length restricting my OAL thus limiting powder capacity which sacrifices velocity.

Just my own thoughts. I really should try some heavier bullets.

If the 60s & 70s are key holing at 100, going heavier/longer will almost certainly make matters worse. The combination of the 12 twist and 6x45 velocities isn't spinning the bullet fast enough to stabilize it. You will need to go lighter, tighter, or faster.
 
Originally Posted By: KlrDrvrOriginally Posted By: BBsteelI have a 1:12 twist Dtech 22" upper in 6x45. I have only run 60 and 70 grain bullets through it. Both weights key hole at 100 yards. Shooting a heavier bullet in an AR didn't appeal to me with mag length restricting my OAL thus limiting powder capacity which sacrifices velocity.

Just my own thoughts. I really should try some heavier bullets.

If the 60s & 70s are key holing at 100, going heavier/longer will almost certainly make matters worse. The combination of the 12 twist and 6x45 velocities isn't spinning the bullet fast enough to stabilize it. You will need to go lighter, tighter, or faster.

That's the way I read BBsteel's comments at first also, but I think by keyholing he means it shoots bugholes.
 
I wasn't sure either. I finally decided that a 12 twist is slow enough that I could imagine 70s keyholing. Perhaps he'll weigh in and clear things up.
 
Sorry fellas. I meant to say bug holing. They are definitely not yawing thus key holing. They shoot clovers at 100.

Hate when I slip up but thankfully have you guys to rely on.


Oops!
 
I have some 1:10 and have shot well with them. My latest match gun has 1:9 from Black Hole and it is shooting very well with 87's. I have not tried any 95's but it would also shoot 90's OK.

I know it won't go past the 100 mark as my 105's have lots of yaw on them.

Greg
 
Originally Posted By: GLShooterI have some 1:10 and have shot well with them. My latest match gun has 1:9 from Black Hole and it is shooting very well with 87's. I have not tried any 95's but it would also shoot 90's OK.

I know it won't go past the 100 mark as my 105's have lots of yaw on them.

Greg

I just finished an upper built around a bhw 1:9. How long are you loading the 87s?
 
Originally Posted By: KlrDrvrOriginally Posted By: GLShooterI have some 1:10 and have shot well with them. My latest match gun has 1:9 from Black Hole and it is shooting very well with 87's. I have not tried any 95's but it would also shoot 90's OK.

I know it won't go past the 100 mark as my 105's have lots of yaw on them.

Greg

I just finished an upper built around a bhw 1:9. How long are you loading the 87s?

I load them mag length and also way out there. There is quite a bit of data on mag length stuff now from Accurate and a few others. I shot some parallel testsusing mag length vs long out to 2.360, single shotted, and found the decrease in accuracy for the short ones was negligible for most uses. Also I did not see much velocity change but I stayed out of the lands on purpose.

Greg

PS: I have quite a few posts on the various things I shoot over at BHW. Look thme over and you might get some ideas.
 
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Thanks guys. I was just looking on 6br.com. They have a lot of good info on barrels including twist rates. After reading that and BBsteel's comment, I'm leaning toward a 12 twist from Dtech.
 
Originally Posted By: LukeWThanks guys. I was just looking on 6br.com. They have a lot of good info on barrels including twist rates. After reading that and BBsteel's comment, I'm leaning toward a 12 twist from Dtech.

I think you will hinder yourself with a 1:12. Go with a 1:10 and you can shoot the 87's. The 1:12 may well be marginal for that. I think if you talk with Mike M. he will second that theory.

One rule of thumb is to buy the fastest twist you need to handle the biggest bullets you MIGHT need down the road. IMHO.

Greg
 
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Originally Posted By: LukeWThanks guys. I was just looking on 6br.com. They have a lot of good info on barrels including twist rates. After reading that and BBsteel's comment, I'm leaning toward a 12 twist from Dtech.

Like GL I suspect 12 may really limit your bullet choices. Thing about the BR guys is many to most of the ones I talk and read like to run on the ragged edge of stability. I can see doing that in a dedicated BR rifle running specifc bullets, but I wouldn't do it in an AR.

I'll be interested to see what happens as BBS move up in weight. If the laws of physics are still working he should be about plateaued where he is. Have a heart to heart with Mike M. I think he'll steer you right.
 
My 24" SS, 1/10" 6x45 twist bbl shoots my handloads of 58vm/65vm/70nbt/80 Nosl part./85 sgkhp/87vm/95 nosler HBT grain bullets all very accurately to 400 yards.
 
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