Major vs. Minor

[Bartholomew Roberts]

As I understand it, the power factors in IPSC and proposed for the new IDSA are meant to represent an advantage that larger caliber guns have in shots that are placed less than perfectly.

I am curious as to what the basis for this assumption is? Is there any evidence to support the idea that in handgun calibers, a larger bullet poorly placed will be any more effective than a smaller bullet poorly placed?

 

[Krag]

Power factors are what they are to keep the Cooperites happy. :banghead:

They have little relevance to USPSA today, which is a sport not defensive training. I think USPSA ought to set a minium caliber and bullet weight and let the shooters go from there. If they need high pressure, hot ammo to make their pistols/compensators, etc. work more efficiently let 'em go for it. Other then that who cares?

 

[waktasz]

I thought the powerfactors are set because it is inherently easier to shoot a lighter round faster and more accurately.

 

[eerw]

power factors were set because when combat shooting started they determined this by the distance a pendelum would move when struck by the bullet..essentially everything was geared to what a 230fmj bullet from a 1911 pistol would do..the weapon decided by Col. Cooper to be the best fighting handgun..

to put that to a quantifiable number and measurable..a formula was established velocity X bullet weight = ### divided by 1000. Then a scoring system to reward the shooter that shot a pistol with that ballastic.

it makes no assumption that light, smaller bullets are less effective with less than COM hits or any thing else. This was also determined decades ago and does not take in account terminal ballistic studies, modern bullet design or anything else..

It is only a scoring system for a particular game established by individuals with a certain bias to a particular weapon and ammunition.

 

[Island Beretta]

Waktasz, Originally this was so but I have shot .40 caliber STI in Limited that felt softer than a 9mm in a Production weapon. May be the weapon but the point is that I could not shoot a 9mm STI in Production due to it being single action..

 

[Zak Smith]

In general, bigger/deeper hole = more blood loss, which is the primary means of incapacitation besides CNS destruction.

IPSC's motto is "Speed - Power - Accuracy"

-z

 

[Krag]

I remember reading an article once where the author stated that IPSC's rules "...were established to insure the supremacy of the 1911 pistol and .45 ACP cartridge." Well, I guess they've achieved half of that?

As they have been progressivly lowering the P.F. for years now I think even the powers that be realize the concept is no longer really defensible.

 

[Bartholomew Roberts]

In general, bigger/deeper hole = more blood loss, which is the primary means of incapacitation besides CNS destruction.

From a gunfight standpoint, how much faster will a .354" hole bleed out when compared to a .450" hole? Is it enough of a difference to justify the scoring difference or is the scoring there simply to keep 1911-style weapons competitive?

 

[Island Beretta]

I think it is based on the 'power' side of the IPSC triangle. but as you said modern developments have rendered this moot..I mean Rob L. is shooting 9mm major in Open now.. others such as David Olhasso prefers a downloaded .40 rather than an uploaded 9mm..they all now can download or uploaded to get the required pf to suit their needs....

 

[Zak Smith]

From a gunfight standpoint, how much faster will a .354" hole bleed out when compared to a .450" hole? Is it enough of a difference to justify the scoring difference or is the scoring there simply to keep 1911-style weapons competitive?

I have no physiological data, but DocGKR might.

As for the 1911, you must mean the 45ACP. 1911 pattern guns in .355 bore size and 40SW dominate IPSC/USPSA.

If you look at the best-rated defensive pistol cartridges, they generally are either :

in 9mm, a 124-127 @ 1200-1300fps, or a 147 @ 1000fps,
in 40SW, a 180gr @ about 1000fps,
in 45ACP, a 230gr JHP.

All of these are either "close to" or exceed the 165PF. So in that sense, the power factor is keeping shooters "honest" instead of shooting wimp loads.

-z

 

[eerw]

Got to remember the powerfactor is based off the 230FMJ from a 5" 1911

that is all...it is the third portion of the IPSC motto DVC..speed power and accuracy...now powerfactor is a moving number.that differentiates between minor and major scoring...

what people shoot..a downloaded .40 vs a 9mm in production, vs 38 super/9mm major vs ..45acp..has no bearing in reality but only the game...

much of that is determined by magazine capacity, powder/bullet choice, manufacture sponsorship and individual shooter preference...not what works on thet street..

 

[Correia]

eerw, you can't get anybody to agree what really works on "the street". In the meantime, the 165 PF keeps us semi-honest and keeps us from shooting loads that barely penetrate cardboard in competition.

 

[eerw]

Correia

agree with ya there...

 

[Krag]

"...loads that barely penetrate cardboard in competition."

Man, now that's an attractive concept!!! :banghead:

 

[Zak Smith]

I thought we were talking about IPSC & IDPA, not High-Power!

 

[sturmruger]

Being able to shoot minor is a big advantage in production guns like my SA XD. I have both a XD9 and a XD40. If I had to time myself I think that the .40 would take me about 10% more time to get the same hits as my 9mm. As I get better at shooting handguns that will probably drop down some, but right now I would say that is a safe number.

The PF is used to keep the playing field as level as possible. I love production because I can shoot minor 9mm.

 

[faustulus]

I just wish they went by pf alone in limited/10. I don't mind shooting hotter nines, to make major in limited. If it is good enough for open is should be good enough for limited.

 

[ted murphy]

FWIW,

Power factor is a pretty simple way to set a standards to ensure a certain level of power and recoil impulse for people to hold to for competitive shooting.

I think it is better than trying to use a chart or try to hold to a minimum kE because it's simpler to measure and calculate.

Before you chould get a chrono for under several hundred bucks a simple ballistic pendulum was a pretty good way to measure power factor- but that is a better measure of momentum than ke or velocity.

I have seen folks want to create a more "real world" test for "major" power ammo, but they all seem too complex to adminster in a competitive setting.

I do find it funny that "major" is 165 pf in USPSA but in limited class, you have to have a minimum of .40 caliber. It's kind of an odd departure when you think of it.

Ted