Muzzle Velocity Question

[JaxNovice]

When an ammo manufacturer publishes the MV of one of their loads, is their a standard barrel length they use for the tests or does it vary?

 

[matrem]

Most will list bbl length.

 

[rcmodel]

Most ammo manufactures do not list barrel length.

You can probably figure on 24" for standard calibers and 26" for Magnums though.

No manufacture is going to advertize velocity figures they got out of a short barrel.

rc

 

[matrem]

Most ammo manufactures do not list barrel length.

Then I'll rephrase that to say most (of the "big players") do.
Yesterday, when I read your OP,I happened to only have three handy:
2009 Remington catalog- It lists test bbl lengths in a note at bottom of page.
2009 Winchester Ammunition catalog- It is similar format to Rem.
2007 Speer Ammunition catalog- It lists bbl lengths right beside the given load.
I don't have access right now to a Federal catalog, so I can't say whether they do.