Barrel Length and Velocity
With all other factors being equal, we know that as we increase barrel length, we gain velocity. But how much? During a Level-II handgun class in Lynchburg Virginia, we decided to quantify this.
Ammunition used was American Eagle 115gr. FMJ 9mmP.
|
Make/Model |
Barrel |
Lowest Vel. |
Highest Vel. |
Avg. Vel. |
Extreme Spread |
Standard Dev. |
|
Taurus PT-99 |
5" |
1212 |
1225 |
1217 |
13 |
7.21 |
|
Kahr Mk9 |
3" |
1036 |
1091 |
1065 |
55 |
27.0 |
In this case, two extra inches of barrel length gave us an additional 152 fps. This is something to keep in mind as we balance size/concealability versus 'power.' The smaller the gun, the easier it is to conceal, but as it gets smaller (barrel-wise), it loses velocity and therefore 'power.'
Then we tested the Smith and Wesson 3913 against the Glock 19. Ammo was Georgia Arms 115gr. FMJ 9mmP.
|
Make/Model |
Barrel |
Lowest Vel. |
Highest Vel. |
Avg. Vel. |
Extreme Spread |
Standard Dev. |
|
Glock 19 |
4.02" |
1135 |
1153 |
1145 |
17.65 |
9.16 |
|
S&W 3913 |
3.5" |
1102 |
1113 |
1123 |
21.19 |
8.54 |
In this case, 1/2 of an inch difference in barrel length resulted in a velocity difference of 22fps. Not quite as significant as the above case.
The moral of the story?? Find an ammunition that 'likes' your gun and performs well in it, both in terms of accuracy as well as velocity.