Why 125000 For Minor

[AzShooter]

I've been searching the threads to see why 125000 is the minimum allowed power factor but can't come up with the reason. Was this an arbitrary number or is there any specific fact that ammo of less power is unsafe?

[Nik Habicht]

I've been searching the threads to see why 125000 is the minimum allowed power factor but can't come up with the reason. Was this an arbitrary number or is there any specific fact that ammo of less power is unsafe?

I'm just guessin' here, but having read Professor Sweeney's accounts of the early days of IPSC --- everyone shoots a 1911 SingleStack in .45ACP; those few who don't shoot a Browning Hi-Power in 9mm --- I'm thinking it's because 125,000 is easily made by most factory 9mm ammo. 115 gr. bullet at 1100 fps = 126.5 PF........

[Chuck Anderson]

It's a combination of what Nik said and another factor. 125 PF is easily made by almost all 9mm ammo. There are a few exceptions but there always will be. The other problem is that we use knockdown steel at our matches. If we start allowing PF under 125 we either need to lower the power needed to drop the steel, which would also make it a lot easier to blow over in the wind. Or we could just use ring and paint for minor guns. Either way gets IPSC away form one of the triad of principles, Accuracy POWER, speed.

[PhilTerry]

The two power factors for major and minor were built around the then two available military rounds the USA issue 45 hardball and the NATO 9-mm.

Ballistic pendulums were used to assess power factor before the advent of the very early chronographs which used circuit breaker cards to time the projectiles - ( I think I have one or two still left in my stack of old shooting stuff).

[Wildman]

We used to use .38 special lead round nose in Federal loadings to give the 125,000 base line for chronoing at Bianchi in the early Eighties. Everyone’s load had to make that number for the day. Seems like we used Chapman’s model 10 4-inch as a base gun.

[AzShooter]

Thanks for all the help.