Variable Rifling [Vanity]

Self ^ | 11 Apr 10 | Self

[OneWingedShark]

Yes, overly academic/theoretical, but I thought some Freepers might have some knowledge/experience/thoughts.

[Travis McGee]

It’s called “gain twist.”

[OneWingedShark]

>It’s called “gain twist.”

Ah, I see... I’ve not heard of it before.
Guess it’s time to bounce to wikipeda and see the basics thereof. {Yes, wikipedia can be a bad source, but it’s generally a good starting point for a lot of non-political or technical stuff.}

[RC one]

The .460 smith and wesson magnum has a gain twist. There’s an article in a fairly recent American Rifleman about it.

[HiTech RedNeck]

Are short guns ever rifled?

[Dexter Morgan]

Like handguns? Yes.

The rifling stabilizes the bullet. I’m not sure why you wouldn’t rifle any modern firearm, unless of course you had a projectile that was inherently stable. Maybe I’ll invent the football lace bullet.

[mamelukesabre]

Keep in mind that a bullet accellerates down the barrel. So even if you have a steady or constant rate of twist, the bullet will experience a progressive rate of twist due to it’s increasing velocity as it travels down the barrel.

[Eagles6]

I think some cap and ball revolvers were/are gain twist rifled, don’t know about rifles. Been in and out of fashion for years obviously. Possibly more applicable to slower velocities and/or heavier projectiles.

[DelaWhere]

Bite your tongue and look up ‘progressive rifling’.

Not in any way associated with liberals/progressives in politics... LOL

[Oceander]

There’s at least one specialty manufacturer that seems to use gain twist (aka progressive twist) rifling, here: http://www.sviguns.com/1201.php

[yarddog]

The Italian Carcano had gain twist rifling. Nothing terribly wrong with it except it has a tendency to wallow out the groove in the bullet due to changing angle as it moves down the bore.

The advantage is the bullet originally hits the rifling as a slow twist which helps keep the bullet from deforming.

I have no idea why S&W chose it.

[OneWingedShark]

>Are short guns ever rifled?

Yes, Sometimes.
I saw a video where they were putting regular shot down one and comparing it to the normal scatter-patterns of a shotgun.
(It tended to make ‘O’ patterns.)

[DelaWhere]

>>>Are short guns ever rifled?<<<

Ummm, Maybe when they get scraped for gonorrhea, maybe they spiral it.

Ok, sorry, couldn’t resist.......

[OneWingedShark]

>Bite your tongue and look up ‘progressive rifling’.

Why ‘bite my tongue’?
I was ignorant, knew my ignorance on the subject, and asked for knowledge.

[HiTech RedNeck]

gross

[mamelukesabre]

Sounds like a gimmick to me. Pointless.

[HiTech RedNeck]

Normally a BS monger in physics, luke actually gets one right. If anything, a slight “loss twist” might make sense if the thrust of propellant combustion gases falls as the projectile nears the muzzle.

[plinyelder]

I ‘Think’ that he was referring to the word: “progressive” in his post. (You know .. Progressives aka: Communists)

No need to get defensive.

[50cal Smokepole]

Good question. I have never heard of gain twist before, but then I just learned about polygonal rifling. Bought a CZ 82 recently and thought I had a freakin' shotgun. (Glocks and H&Ks also have polygonal rifling.)
(Grooved rifling on the left, polygonal on the right.)

[HiTech RedNeck]

And then you wonder why subsequent kids are screwed up.