Twist Rate/Muzzle Velocity Question

[10ring'r]

I've had this question in the back of my head at certain times in my shooting career.
Does twist rate effect muzzle velocity?
In my mushy Grey Matter, I would think, that the faster/tighter the twist, the slower the bullet would exit the barrel, all things being the same of course (barrel, ammo, temp., alt., blah, blah, blah). Reason being, more "friction", due to a smidge more rifling/lands in, say, an 18" barrel.
My theory, anyways, a 1-n-9 twist would exit the barrel at a higher muzzle velocity, than a 1-n-7 twist. Due to less "friction" and less lands (rifling) in the barrel.
I realize, we are talking hundredths of inches, possibly less, possibly more. I do understand, the faster the twist, the more accurate a certain weight/length bullet is, and the fact that lighter/shorter/thin jacketed bullets will vaporize in a too fast of a twist barrel.
Just curious if this is a correct assumption, or I'm dumber than I originally thought.
Please don't hate me, I didn't Google Foo this, just popped into my head while I was watching the snow flurries blow around outside.
Thanks in advance for squaring me up and setting me straight.
Ok, let the twist rate games begin!
Mac

 

[bfoosh006]

Short answer... no.

You will find there is a typically a higher difference ( extreme spread ) between firing the same brand ammo in the same barrel.

https://bulletin.accurateshooter.co...-twist-rate-affect-muzzle-velocity-litz-test/

 

[longshot2000]

But a slower twist may allow you to load to a higher velocity by reducing pressure.....

Never quite thought about it that way, but makes sense.

 

[10ring'r]

Short answer... no.

You will find there is a typically a higher difference ( extreme spread ) between firing the same brand ammo in the same barrel.

https://bulletin.accurateshooter.co...-twist-rate-affect-muzzle-velocity-litz-test/

Ahhhh, Bryan Litz! Should have known. Thanks for the link. Mac

 

[308pirate]

Does twist rate effect muzzle velocity?

In theory yes.

In practice, you cannot measure the difference.

Now I will sit back and watch all the people with zero knowledge of Newtonian physics argue this.

 

[Steel head]

In theory yes.

In practice, you cannot measure the difference.

Now I will sit back and watch all the people with zero knowledge of Newtonian physics argue this.

 

[308pirate]

View attachment 7743538

Physics, not chemistry

 

[hlee]

Physics, not chemistry

Chemistry is just applied physics...

 

[10ring'r]

In theory yes.

In practice, you cannot measure the difference.

Now I will sit back and watch all the people with zero knowledge of Newtonian physics argue this.

Yep, I realized that "IF" there was a difference, it would be miniscule.
Just something I often thought about during my conversations with other shooters. Most would just shrug, and say.....F! I just don't know? Me included. More of a curiosity thing. Thanks! Mac

 

[spife7980]

Physics, not chemistry

 

[308pirate]

Chemistry is just applied physics...

LOL I think not

Seems like you failed both

 

[GONE BAD]

Then why do we have 'gain' twist barrels?
YMMV. LOL

 

[hlee]

LOL I think not

Seems like you failed both

Don’t tell the dean of the school of Nat Sci at U Texas. S/he might send someone to confiscate my PhD.

Some autistic physics major laid that little nugget on me freshman year. “Why you majoring in chemistry? It’s just applied physics…” I LOLed too, before ‘LOL’ was a thing.

 

[bfoosh006]

Then why do we have 'gain' twist barrels?
YMMV. LOL

Gain twist has been my "I've had this question in the back of my head at certain times in my shooting career."

https://www.snipershide.com/shooting/threads/gain-twist-barrels.6872099/
From Bartlein:
"For the most part, I would say there is no velocity gain in a gain twist barrel with the same load. What has been conveyed to us and it goes back to Popes 1st point is that shooters have noticed that they can run a slightly heavier powder charge vs. a shooter with a straight twist barrel. As the bullet is starting easier into the rifling my only guess is the pressure isn’t spiking as fast or is delaying the pressure curve. Hence forth they can get more velocity out of the gain twist barrel. I feel pressure is pressure and that the twist doesn’t have anything to do with pressure for the most part but my only guess is that the gain twist like I said earlier is delaying the pressure curve. So you don’t see problems as early like hard bolt lift etc"