Gain-Twist Rifling: Why did it flounder?

[asp]

I'm looking for a history lesson. I realize that it would be harder to manufacture and perhaps require different ballistic calculations, but it seems like an easy way to get more longevity out of a barrel. Thanks in advance.

 

[inerlogic]

it's used in artillery......
my W.A.G. is any or all of the following come into play:

1) expensive to implement on small arms
2) no gains to be had due to length of barrel involved (going from 1 in 12 to 1 in 6 in a 20" barrel is probably useless....)
3) no gains to be had due to projectile weight, size.... (an artillery projectile being much larger and a million times heavier may need a slow twist rate at first to more easily overcome inertia....)

 

[KBCraig]

As far as I know, it's simply for ease of manufacturing. Gain twist offers no real advantage these days, what with improved metallurgy and jacketed bullets.

In the days of soft bullets, they would simply strip if launched into the rifling at high velocity, so gain twist let them "speed up", so to speak. Ballistics would be the same, because they're determined by the velocity and spin at the instant the bullet leaves the barrel.

Heat, pressure, and velocity cause barrel erosion. A smoothbore would wear out just as fast in a .22-250 as a rifled barrel does.

 

[Supermoto]

Scheumann barrel use it. Works great

 

[asp]

Thanks John (inerlogic). I didn't realize artillery used it. Neat. Not saying you're wrong. I bet you're on the right track, but I guess I'm thinking more along the lines of the magnum rifle cartridges like .300 RUM, .338 RUM, .338 Lapua, etc. I could see it making a difference in barrel life there, but you're probably right that not so much for stuff like .308.

Edit:

As far as I know, it's simply for ease of manufacturing. Gain twist offers no real advantage these days, what with improved metallurgy and jacketed bullets.

In the days of soft bullets, they would simply strip if launched into the rifling at high velocity, so gain twist let them "speed up", so to speak. Ballistics would be the same, because they're determined by the velocity and spin at the instant the bullet leaves the barrel.

Heat, pressure, and velocity cause barrel erosion. A smoothbore would wear out just as fast in a .22-250 as a rifled barrel does.

1st two points I'm definitely on board with.

#3 I have no experience with, but your example is intriguing. Just playing devil's advocate here- why do they still use it in artillery? Maybe it's to the point that it's just too far past the limit of the material, I don't know.

Scheumann barrel use it. Works great

I'll have to look that up. I'm not saying it doesn't work, but it's kind of like the BetaMax. Even though it was at least as good as the competitor, it didn't take off.

 

[ARV]

Carcano's used it for a while.

 

[KBCraig]

#3 I have no experience with, but your example is intriguing. Just playing devil's advocate here- why do they still use it in artillery?

Although I'm an old Redleg, I don't know. I suspect it's exactly as inerlogic said: the sheer mass of the projectile is harder to get up to proper rotational velocity without stripping the soft brass obturating bands.

 

[Rob Boudrie]

The introduction of CNC driven broach cutting of rifling in handgun barrels makes gain twist something that can be done without additional costs (other than some programming) over conventional rifling, which is what has made this practical for Schuemann and Infinity.

 

[Zappa]

The introduction of CNC driven broach cutting of rifling in handgun barrels makes gain twist something that can be done without additional costs (other than some programming) over conventional rifling, which is what has made this practical for Schuemann and Infinity.

I have a Strayer-Voight infinity wide body 1911 with an OEM Schuemann barrel, do these use gain twist rifling ???
I never suspected that it did, didn't know they used it, but the gun sure is accurate.

 

[Dan S]

Not all Schuemann barrels are gain twist. I think it's the AET barrels.