Max velosity

[Pofoo]

Does anyone know at what barrel length a 38 spl or 357 mag reach their max velosities?
At longer lengths, does the velosity drop off much, as in the case of 16" to 24" rifles?

[RR.44]

It depends on several things, bullet wt, powder charge,powder type, bullet design type, too many variables to say. Be more specific

[Whatisthis?]

It depends on several things, bullet wt, powder charge,powder type, bullet design type, too many variables to say. Be more specific

This.

[NapalmCheese]

http://www.ballisticsbytheinch.com

[Pofoo]

http://www.ballisticsbytheinch.com

Great site, thank you.

[rdfact]

http://www.ballisticsbytheinch.com

This site has some interesting test results. In all but one brand of ammo, the .357 had higher velocities from a 16" barrel than a 17" or 18", and everything shorter than 16". No tests on anything over 18".

Comparing a Stoeger buntline 18" barrel to a Winchester 94AE 16" barrel, some ammo achieved as much as 320 fps more from the 16" Winchester.

http://www.ballisticsbytheinch.com/357mag.html

I asked a local indoor range if I could fire my Marlin 1894C (.357 in 16" barrel) and they said yes. I may want to check again - I thought they had a 1500 fps limit.

[NapalmCheese]

Yuppers, at some point the expanding gases have completely expanded and filled the available volume in the chamber and barrel and no longer add velocity. If the total volume of the barrel and chamber is greater than the volume created by the expanding gases you'll lose velocity from friction and also by making a bit of a vacuum. I don't know how much the vacuum contributes to velocity loss, I just think it's neat.

[russ69]

The 357 mag is meant for pistol length barrels. The loading is tailored for that. I'm sure you could change to a slower powder and get better results.