progressive rifle twist

rdale501 · 01-21-2008, 01:40 PM

Anyone heard of a progressive rifling twist. I heard of this for the first time at the range on Sunday. From what I understand, the twist starts out at a slow twist, then increases as the bullet moves down the barrel. So maybe it starts out at a 1 in 20 and slowly increase to a 1 in 8. Anyway I have never heard of such a thing but didn't want to call the guy on it before checking around. Thought I might run it around here for awhile and see what happens.

troy2000 · 01-21-2008, 01:43 PM

It exists, or at least did in older guns. It's also called, "gain-twist." In military weapons, I believe they decided it wasn't worth the extra cost and trouble.

Nelson · 01-21-2008, 01:44 PM

You pretty much got it. It was used on a few rifles in the past, cant remember which ones off the top of my head, but it never really caught on, not sure why though.

nathangdad · 01-21-2008, 02:48 PM

Yes, it was also called gain twist rifling by some people. It was a logical thing to try. However, it did not seem to produce any increase in accuracy, bullet velocity, etc. and therefore did not continue in the marketplace. You will probably find someone, somewhere that swears by this method but facts are facts and it just did not work out as something worthwhile.

SwedeSteve · 01-21-2008, 05:44 PM

News to me! Thanks for the info guys...

billy · 01-21-2008, 05:49 PM

ive read about that in old army revolvers.

Quote:

Originally Posted by Nelson

You pretty much got it. It was used on a few rifles in the past, cant remember which ones off the top of my head, but it never really caught on, not sure why though.

91- Mannlicher- carcano's had it for awhile

lefty o · 01-21-2008, 06:55 PM

gain twist is still used in some military weapons, and also available in aftermarket 1911 barrels.

just_a_car · 01-21-2008, 08:45 PM

It actually makes a lot of sense for someone like me that's interested in loading up some sub-sonic 7.62x39 rounds with 200-240gr bullets. You'd really need that progressive twist rate to get the proper spin so that it would stabilize.

troy2000 · 01-21-2008, 09:33 PM

Earlier today, I was reading comments by a custom barrel-maker. unfortunately I can't find them again, and I didn't get his name.

He said he used to do the progressive rifling. but years of careful testing finally convinced him that he could get better accuracy by concentrating on making his rifling as close to perfectly even from end to end as possible, instead.

SwedeSteve · 01-22-2008, 01:25 AM

JAC & T2k- Points well taken. T2k- What about subsonic? Any specific barrel length JAC?

dogman2 · 01-22-2008, 02:40 AM

Smith & Wesson uses gain twist in the 500 and 460. It's to keep the bullet from skidding on the rifling.

just_a_car · 01-22-2008, 05:01 AM

Quote:

Originally Posted by SwedeSteve

JAC & T2k- Points well taken. T2k- What about subsonic? Any specific barrel length JAC?

Well, I'm thinking around 21-24", since that's where the AES-10 and SKS sit for barrel length. I can't wait to start handloading so that I can put some together to try in my AES-10, though I'm thinking that the fact that it will be so little gas from to get it sub-sonic that the bolt won't cycle in the semi-auto. That's not a problem in an SKS, though, if you turn off the gas port.

01-21-2008, 01:40 PM	#1
rdale501 Senior Member Join Date: Sep 2007 Location: oregon Posts: 398	progressive rifle twist Anyone heard of a progressive rifling twist. I heard of this for the first time at the range on Sunday. From what I understand, the twist starts out at a slow twist, then increases as the bullet moves down the barrel. So maybe it starts out at a 1 in 20 and slowly increase to a 1 in 8. Anyway I have never heard of such a thing but didn't want to call the guy on it before checking around. Thought I might run it around here for awhile and see what happens.

01-21-2008, 01:43 PM	#2
troy2000 Resident Armed Liberal Join Date: Dec 2004 Location: Southern California Posts: 9,459 Images: 9	It exists, or at least did in older guns. It's also called, "gain-twist." In military weapons, I believe they decided it wasn't worth the extra cost and trouble. __________________ If a million people say a foolish thing, it is still a foolish thing. -Anatole France Last edited by troy2000; 01-21-2008 at 01:46 PM.

01-21-2008, 02:48 PM	#4
nathangdad Senior Member Join Date: Nov 2007 Posts: 2,475	Yes, it is true Yes, it was also called gain twist rifling by some people. It was a logical thing to try. However, it did not seem to produce any increase in accuracy, bullet velocity, etc. and therefore did not continue in the marketplace. You will probably find someone, somewhere that swears by this method but facts are facts and it just did not work out as something worthwhile.

01-21-2008, 05:44 PM	#5
SwedeSteve Thor's Hammer Join Date: Feb 2007 Location: Alaska Posts: 10,372 Images: 1	News to me! Thanks for the info guys... __________________ Thank God we don't get as much Government as we pay for! -Will Rogers

01-21-2008, 08:45 PM	#8
just_a_car Senior Member Join Date: Oct 2006 Location: Edmonds, WA Posts: 3,522	It actually makes a lot of sense for someone like me that's interested in loading up some sub-sonic 7.62x39 rounds with 200-240gr bullets. You'd really need that progressive twist rate to get the proper spin so that it would stabilize. __________________

01-21-2008, 01:44 PM	#3
Nelson Registered User Join Date: Dec 2007 Location: Norfolk, VA Posts: 14	You pretty much got it. It was used on a few rifles in the past, cant remember which ones off the top of my head, but it never really caught on, not sure why though.

01-21-2008, 06:55 PM	#7
lefty o Senior Member Join Date: Mar 2002 Location: mn Posts: 4,806	gain twist is still used in some military weapons, and also available in aftermarket 1911 barrels.

01-21-2008, 09:33 PM	#9
troy2000 Resident Armed Liberal Join Date: Dec 2004 Location: Southern California Posts: 9,459 Images: 9	Earlier today, I was reading comments by a custom barrel-maker. unfortunately I can't find them again, and I didn't get his name. He said he used to do the progressive rifling. but years of careful testing finally convinced him that he could get better accuracy by concentrating on making his rifling as close to perfectly even from end to end as possible, instead. __________________ If a million people say a foolish thing, it is still a foolish thing. -Anatole France

01-22-2008, 01:25 AM	#10
SwedeSteve Thor's Hammer Join Date: Feb 2007 Location: Alaska Posts: 10,372 Images: 1	JAC & T2k- Points well taken. T2k- What about subsonic? Any specific barrel length JAC? __________________ Thank God we don't get as much Government as we pay for! -Will Rogers

01-22-2008, 02:40 AM	#11
dogman2 Banned Join Date: Dec 2007 Location: Iowa Posts: 133	Smith & Wesson uses gain twist in the 500 and 460. It's to keep the bullet from skidding on the rifling.