[71dartswinger]

With my 24/7 C, I have a 3.3" barrel where all stats for the .40 S&W are with a 4.0 barrel. Does the shorter barrel create less pressure or does the max pressure occur just as the bullet is leaving the case of the shell? Another question, how much does the shorter barrel reduce velocity? I can't seem to find any information if it is a linear loss or what.

 

[jwc007]

Pressure Statistics are Peak Chamber Pressure, which occurs as the Bullet starts to leave the Shell Casing, as you have surmised. Pressure will decrease as the Bullet travels down the barrel, due to the expanding burning area.

Barrel Velocity losses will depend upon the burning rate of the powder used for the particular load. Most defensive ammunition made today, with the exception of the Magnums, are formulated to make efficient use of the shorter barrel lengths found on todays CCW handguns.

Velocity losses in the .40 S&W can range between 5% and 15% depending upon the Ammunition used. Only a Chronograph can tell you exactly.

 

[71dartswinger]

Thanks for the reply! I think I have it figured out now lol.

 

[Gray_Wolf]

+1 for what jwc007 said.

.40 caliber uses fairly fast burning powders so the velocity loss should not be that singificant. (but the rule is; longet the barrel the higher the velocty.)

Edit: I would recommand Power Pistol if you want full power loads (and still be under +p)