Barrel twist 1:7.5 or 1:8

[Montanaatheart]

Howdy all. Just looking for some insight on how much one can expect a difference in speeds (if any) if all things being equal ((they never are -barrel length and load - same reamer created both))? I realize barrels vary so am just more of a general expectation, if one has a 4r 1:8 compared to a 5r 1:7.5.

 

[Varmint Hunter]

Howdy all. Just looking for some insight on how much one can expect a difference in speeds (if any) if all things being equal ((they never are -barrel length and load - same reamer created both))? I realize barrels vary so am just more of a general expectation, if one has a 4r 1:8 compared to a 5r 1:7.5.

From a practical standpoint - no difference in speed. If you went from a 14" twist to an 8" twist than, maybe, there would be a measurable difference, but I doubt that it would be meaningful.

 

[FEENIX]

Howdy all. Just looking for some insight on how much one can expect a difference in speeds (if any) if all things being equal ((they never are -barrel length and load - same reamer created both))? I realize barrels vary so am just more of a general expectation, if one has a 4r 1:8 compared to a 5r 1:7.5.

I agree with @Varmint Hunter. On my last three builds, I went with "or faster" for the twist recommendation of the bullets I am using: .257 WBY and .264 WM are 1:7" and .338 Thor is 1:8", and so far, so good.

 

[MagnumManiac]

It has been measured many times twist and number of grooves has very little affect on velocity, but WIDTH of rifling does, albeit a very small amount.
If anybody remembers 'micro-groove' barrels, these were faster than Ballard type rifling, but fouled in less than a 1/4 number of shots.
I had one, what a DISASTER that was.

Cheers.