17 HMR barrel length

[JTO]

Would the twist rate make a difference to the optimum barrel length?

 

[stevenedwards]

I know I said it looks like less is more but.... now Im wondering about .17 hornet. Not a wide range of platforms available as far as I can see, going to enquire about component availability.

 

[Squirrelbasher]

And of course that velocity loss is measured at the muzzle. Down range where it matters there will probably be no difference, or the drop will be even smaller.
I'm sure I read somewhere that a barrel greater than 16" on an HMR actually reduces velocity as well, as the cartridge completes its burn within 16" so any additional length only acts as a drag on the projectile. Don't know if that's trues but it sounds reasonable.

Yes, measured at the muzzle, no noticeable difference in down range performance.

 

[C h r i s]

Found a well written report a couple of years ago that claimed 18" / 19" was the optimal barrel length for 17HMR for maximum velocity (doing a barrel chop from 22" down to 10"). However the resulting loss for a slightly shorter barrel shouldn't be a massive issue. If you really need speed then look for a .17 centrfire instead.

17 HMR Velocity Data | Bullberry Barrel Works, Ltd. | United States

 

[Dave_424]

Found a well written report a couple of years ago that claimed 18" / 19" was the optimal barrel length for 17HMR for maximum velocity (doing a barrel chop from 22" down to 10"). However the resulting loss for a slightly shorter barrel shouldn't be a massive issue. If you really need speed then look for a .17 centrfire instead.

17 HMR Velocity Data | Bullberry Barrel Works, Ltd. | United States

Interesting to see the longer barrels having larger FPS spreads. I would assume that's down to inconsistency in friction between the bullet and the bore over the last 4 inches as by 18" the bullet has reached maximum velocity.