trying to understand power factor.

[Madball6]

Can someone give me the "Idiots guide to Power Factor."? I'm interested in trying to get involved with defensive practical shooting competitions, but i dont understand the whole power factor consideration. Hoping to get an explanation in laymans terms although im not afraid of the math that may or may not be involved. I'm just confused about 9mm vs 40S&W vs 45acp. Im looking at starting in a production division, but not necessarily staying there. Just looking to get my feet wet. But i have several handguns and was just wondering about power factor and if i should bring one over another due to scoring. I'm honestly not trying to win anything, im a decent shot with all my pistols, but i think getting into some of these competitions may make me a better shooter. Just want more info into what i may be getting into.

-Keith

 

[gunrobot]

Power factor is really simple. Bullet weight x Velocity

you'll measure bullet weight by grains, typical weight for 9mm is 115gr, 124gr and 147gr, 45 ACP 200gr and 230grs.

Velocity is measured using a chronograph, shoot 5-10 rounds through a chrono and get the average feet per second (FPS).

As an example, I'll use my 45 ACP load, 230gr, average fps is 750.

230x750 = 172,500 or 172pf.​

Depending on which game you're playing, IDPA refers to it as 172,000pf and USPSA 172 pf.

There are two types of power factor that are used in competition shooting : MAJOR and MINOR.

Minor is 125 to 164 pf, Major is anything greater than or equal to 165. so my 172pf load makes Major powerfactor. If you're shooting production, you only have to worry about making Minor pf, so anything above 125pf.

hope that helps.

here's a wiki entry on PowerFactor : http://en.wikipedia.org/wiki/Power_factor_(pistol)

 

[Don P]

Major and minor(caliber) are for scoring purposes in USPSA.
If you choose to shoot IDPA caliber will have NO bearing with regards to scoring.
In both disciplines IF you re-load your ammo must meet the minimum required feet per second or power factor. At the local level ammo is not checked. At a state or national match ammo is checked using a chrono to see how fast your ammo is moving. If your ammo passes you are good to go. If your ammo fails you are DQ'ed and your shooting is all done for the match.