Quoted Velocities - different pistol to rifle?

[Charlotte the flyer]

Just loading up some 9mm, have settled on 125gn lead round nose with 4.7gn of Bullseye. Have used the Lee die instructions and also checked a reloading manual and the interweb and the same figures keep coming up so I'm going with them.

One question on velocity, I'm reading 1165FPS everywhere but won't it be different depending on what the round is shot out of? I've heard people on the range query velocities with an 'ahh but that's out of a pistol, it'll be higher out of a rifle'. Is there a multiplier that I can add to work out the difference or does that only apply to higher powered cartridges (think it was in relation to a 44)

Thanks

Charlotte.

[kennyc]

longer barrel =more burn time = more acceleration time =more MV its probably dealt with in the reloading manuals as a table rather than a multiplier,and there will come a point where friction and 100% burn will result in a drop in MV rather than an increase .

[dodgyrog]

Longer barrel - I'd use Viht 3N37 or 340 by preference - lower pressures and higher velocities

[Chapuis]

The books will only give you an indication of velocity out of a test barrel of a stated length Charlotte. To find out what the actual velocity is out of your rifle/carbine you are going to have to use a chronograph.

[Sandgroper]

Ballistics by the inch should give you a ballpark figure http://www.ballisticsbytheinch.com/