Ole
03-07-2011, 10:44 PM
Loading the same exact bullet with the same exact powder charge, the 9mm produces about 200-300fps more velocity than a .38 special.
Powder is 3.7 grains of Bullseye and the bullet is Lee 125gr RNFP lead. As cast in the .38 and sized .357" in the 9mm. Pistols are 4" SW model 59 and a Ruger GP100 4".
Extra case capacity for the .38 and higher pressure limit for 9mm is what's going on here I take it, but how does it work to a layman? How do you get an extra 200-300fps out of a smaller case simply by running a higher pressure limit?
Maybe the revolver cylinder gap accounts for part of it?
Just wondering to myself how this could happen. I mean the same powder charge should propel the same bullet the same speed, one would think.
Does running higher pressure out of a smaller case automatically mean more velocity out of the same powder charge? :veryconfu
Powder is 3.7 grains of Bullseye and the bullet is Lee 125gr RNFP lead. As cast in the .38 and sized .357" in the 9mm. Pistols are 4" SW model 59 and a Ruger GP100 4".
Extra case capacity for the .38 and higher pressure limit for 9mm is what's going on here I take it, but how does it work to a layman? How do you get an extra 200-300fps out of a smaller case simply by running a higher pressure limit?
Maybe the revolver cylinder gap accounts for part of it?
Just wondering to myself how this could happen. I mean the same powder charge should propel the same bullet the same speed, one would think.
Does running higher pressure out of a smaller case automatically mean more velocity out of the same powder charge? :veryconfu