Power factors??

Texas Solo · June 11, 2008, 11:03 PM

Can somebody explain how to calculte this, and how I could get "major" out of a 9mm?

glockopop · June 12, 2008, 12:41 AM

Power factor is the weight of the bullet in grains times the velocity in feet per second divided by 1000. For example:

230gr. bullet
800fps velocity

(230x800)/1000=184 power factor.

9mm Major is possible, but you will be exceeding SAAMI specs for pressure and should only be attempted in guns that can handle it. Many actually can. There is actually a factory loaded Winchester Ranger 127gr. +p+ round that makes major.

In USPSA shooting, major 9mm is only legal for open division. In Limited and Single Stack divisions you can only make major with a .40 caliber or larger bullet. There's nothing that says you can't shoot 9mm Major in Limited, but you'll still be scored minor so there's no point.

Texas Solo · June 12, 2008, 07:09 AM

OK, then I have a problem. I'm wanting to build a race gun out of my G17. I can shoot unlimited with it, but pay a hefty price for not making major...right? Something like double the penalty points?

SDC · June 12, 2008, 07:56 AM

The "penalty" is only that you lose more points for outer hits; if you shoot an "A" with a 9mm, you get exactly the same score as if you shoot that "A" with a .40 or .45. So, the solution is to concentrate on shooting accurately, which you should hopefully be doing anyway, and if you can do that, you don't really need the "Major" crutch regardless.

Jim Watson · June 12, 2008, 07:56 AM

Penalty points are the same. Scoring is where the major-minor difference comes in. Hit them in the "A" zone and all calibers are equal, it is just when you stray into B, C, and especially D zones that the smallbore is at a disadvantage.

Do you have a copy of the rule book or know about www.uspsa.org?

Texas Solo · June 12, 2008, 08:34 AM

I'm new to all this, so you'll have to forgive my incorrect terminology. I now understand the POINT scoring diference between Major & Minor. It's a no-briner...just shoot all A's !! I really don't care about where I would place in a match, I shoot against myself. I just want to particiapte and have fun. Thanks for the info.

T. O'Heir · July 6, 2008, 03:32 AM

"...I just want to participate and have fun..." Then just go shoot and forget about everything else. Mind you, if you're in the least bit competitive, you won't be happy just shooting for long. However, hitting the 'bullseye'(the "A" zone) on an IPSC/IDPA(neither of which are in the least bit practical. They're both shooting games and nothing more) target with a "minor" calibre makes the Major & Minor stuff go away.

June 11, 2008, 11:03 PM	#1
Texas Solo Senior Member Join Date: May 3, 2008 Location: San Antonio, Texas Posts: 169	Power factors?? Can somebody explain how to calculte this, and how I could get "major" out of a 9mm?

June 12, 2008, 12:41 AM	#2
glockopop Senior Member Join Date: December 15, 2005 Location: Southern Indiana Posts: 922	Power factor is the weight of the bullet in grains times the velocity in feet per second divided by 1000. For example: 230gr. bullet 800fps velocity (230x800)/1000=184 power factor. 9mm Major is possible, but you will be exceeding SAAMI specs for pressure and should only be attempted in guns that can handle it. Many actually can. There is actually a factory loaded Winchester Ranger 127gr. +p+ round that makes major. In USPSA shooting, major 9mm is only legal for open division. In Limited and Single Stack divisions you can only make major with a .40 caliber or larger bullet. There's nothing that says you can't shoot 9mm Major in Limited, but you'll still be scored minor so there's no point. __________________ I've only got two hands, but I've been known to carry three Glocks. RZA

June 12, 2008, 07:56 AM	#4
SDC Senior Member Join Date: January 23, 2001 Location: People's Republic of Kanada Posts: 1,652	The "penalty" is only that you lose more points for outer hits; if you shoot an "A" with a 9mm, you get exactly the same score as if you shoot that "A" with a .40 or .45. So, the solution is to concentrate on shooting accurately, which you should hopefully be doing anyway, and if you can do that, you don't really need the "Major" crutch regardless. __________________ Gun control in Canada: making the streets safer for rapists, muggers, and other violent criminals since 1936.

July 6, 2008, 03:32 AM	#7
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...I just want to participate and have fun..." Then just go shoot and forget about everything else. Mind you, if you're in the least bit competitive, you won't be happy just shooting for long. However, hitting the 'bullseye'(the "A" zone) on an IPSC/IDPA(neither of which are in the least bit practical. They're both shooting games and nothing more) target with a "minor" calibre makes the Major & Minor stuff go away. __________________ Spelling and grammar count!

June 12, 2008, 07:09 AM	#3
Texas Solo Senior Member Join Date: May 3, 2008 Location: San Antonio, Texas Posts: 169	OK, then I have a problem. I'm wanting to build a race gun out of my G17. I can shoot unlimited with it, but pay a hefty price for not making major...right? Something like double the penalty points?

June 12, 2008, 07:56 AM	#5
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,535	Penalty points are the same. Scoring is where the major-minor difference comes in. Hit them in the "A" zone and all calibers are equal, it is just when you stray into B, C, and especially D zones that the smallbore is at a disadvantage. Do you have a copy of the rule book or know about www.uspsa.org?

June 12, 2008, 08:34 AM	#6
Texas Solo Senior Member Join Date: May 3, 2008 Location: San Antonio, Texas Posts: 169	I'm new to all this, so you'll have to forgive my incorrect terminology. I now understand the POINT scoring diference between Major & Minor. It's a no-briner...just shoot all A's !! I really don't care about where I would place in a match, I shoot against myself. I just want to particiapte and have fun. Thanks for the info.