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IDPA Power Factor Question
Posted: Sat Jan 06, 2007 5:20 am
by TEX
I have a question about custom loads for IDPA that meet the power factor. In terms of recoil control, which has a more adverse effect, bullet weight or velocity. I am guessing, based on my own observations, that a lighter bullet moving faster is easier to control and recover from recoil than a heavier bullet moving slower – both being at same power factor. In fact, I recently overheard someone say that 40S&W loads of 180g at minimum IDPA legal velocity, actually resulted in less recoil than a 9x19. Wondering if anyone has actually experimented with such things and what your observations were.
I am going to give CDP a try next year and trying to decide if I will be better off with 230g, 180g, or 165g moving at about 5% above the power factor floor.
Thanks - TEX
Posted: Sat Jan 06, 2007 8:33 am
by SRVA
Tex, Recoil is recoil. Thechnically, any load that makes power factor should have the same recoil energy. If you run various power factor loads on a recoil calculator, they come out pretty much the same.
That said, recoil is also very subjective. Recoil velocity, pulse, muzzle blast, handgun design, grip, stance and a host of other things all contribute to the shooter's perceived recoil and their ability to recover.
Some people like heavy bullets going slow because these loads tend to create less muzzle blast and have a slower (read "softer") recoil pulse. Some people, like my wife, need the lighter bullets going faster because the higher slide velocity cycles the slide faster. This prevents some malfunctions for her due to her lower upper body mass.
For me, in 9mm, I prefer lighter bullets in 40, I have found the 165 grain to my likeing and in 45, I prefer the 230 grainers. Bottom line is, try a couple hundred light, mid-weight, and heavy weight bullets in the caliber you intend to use. Load them to power factor and pick the one that feels best to you and provides 100% reliability in your handgun.
DON'T fall into the trap of trying to develop a super soft shooting magic load and trying to adjust your gun to make it function. I have seen this done numerous times by shooters and it normally leads to a long season of frustration, followed by returning everything to factory stock.
Recoil and Power Factor
Posted: Mon Jan 08, 2007 3:23 pm
by Norm Lee
At a given power factor the contribution from the bullet and its velocity will be the same whatever choices you make to get the velocity times bullet mass product to the desired level. The only thing left to play with is the powder you use. Since the powder, converted to gas, is going to be moving at a pretty good clip (it's usually assumed to be in the order of 4000fps) the contribution to the momentum the shooter must absorb is not trivial. That is, the massXvelocity of the bullet plus the massXvelocity of the gas must be reacted by the shooter.
So the "secret" is to use a relatively heavy bullet with as little powder as needed to get the required velocity. This must be managed pretty carefully, since relatively fast burning powders are the ones you'd pick for lowest mass and the combination of fast powder and heavy bullet can get exciting in a hurry.
Cheers,
Norm
Posted: Mon Jan 08, 2007 4:32 pm
by HighVelocity
I shoot whatever makes power, functions in the pistol and hits POA at 15 yards. The only way to know for sure is to chronograph the ammo in YOUR gun and shoot that ammo a LOT.
Posted: Tue Jan 09, 2007 2:40 am
by TEX
Norm Lee,
Thanks for the rely. You answered the question I was trying to ask. Your reply leads me to belive that the heaviest avilable bullet moving just fast enough to make power factor may present the most managable recoil. This sort of explains why some have gone to the 40S&W moving at 700 fps in SSP. I heard someone comment that the recoil is less than any 9mm load making the power factor. I have always shot a 40 in SSP, but always used off the self practice ammo (Blaser, Magtech, etc.)
From what you have said, in CDP, a 230 grain slug consistantly moving at about 725 fps would make PF and have the most managable recoil. I know that is pellet speed realm and seems like gaming, but it seems a lot of people are taking this approach. I guess there will always be gamers. I see folks shoot at IDPA matches with stuff I know they don't carry on the street. I was looking for a load I can use in major matches that might offer me an edge, but wasn't sure if I should go light and fast or heavy and slow. I figured someone out there whop reloads, had played with this puzzle at one time or another.
Thanks - TEX
Posted: Tue Jan 09, 2007 7:32 am
by SRVA
Tex, Just make sure that any load you use will penetrate the cardboard. It really looks bad to have a bullet stuck in the target.
Posted: Tue Jan 09, 2007 8:59 am
by jbirds1210
I was shooting at a match in Dripping Springs over the summer and had to shoot a steel about four times and a reshoot with 9mm. The old boy that was SO'ing the match looked down at me and asked:
"Are ya loadin those things with baby powder son?"
For the record I was shooting Winchester white box 115 gr on steel that must have been made for shotguns.
Jason
Posted: Tue Jan 09, 2007 11:20 am
by Skiprr
SRVA wrote:Tex, Just make sure that any load you use will penetrate the cardboard. It really looks bad to have a bullet stuck in the target.
One daily humor point for Steve.

Posted: Tue Jan 09, 2007 5:29 pm
by age_ranger
I'm not sure exactly why people need to shoot the power puff girl reloads. In my opinion, if you're gonna be shooting in an IDPA match, you should man up a little and just man handle that flame spoutin' smoke wagon you've been pampering and buy or reload ammo that works reliably. I've seen plenty of people who left matches (DNF) because their reloads wouldn't cycle or feed correctly. Other times you hear them with mixed ammo or inconsistent reloads and it sounds like pfft, pop, pop, pop, pfft, pop, pfft.
Brilliant!!!
Posted: Wed Jan 10, 2007 2:46 pm
by casselthief
ummm, not to be a stickler here, but it's actually the Powder Puff Girls.
and before ya'll get any ideas, I have a 10yrold step-daughter, so that's how I know that.....
other than that, I agree with what AgeRanger said. to me, you outta use what you're going to be carrying in that, proverbial, smoke wagon.
Posted: Wed Jan 10, 2007 2:59 pm
by hi-power
casselthief wrote:ummm, not to be a stickler here, but it's actually the Powder Puff Girls.
*Ahem!*
http://www.cartoonnetwork.com/tv_shows/ppg/index.html
Carry on.
Posted: Wed Jan 10, 2007 3:06 pm
by casselthief
holy crap!
where in the samhain did I get Powder? maybe that's the coke-head alter egos!
*hangs head in shame*
edit: found this off of Google
Powder Puff Girls site
Posted: Wed Jan 10, 2007 5:12 pm
by age_ranger
mmm, hmmmm.......I have a 5 yr old daughter and we watch it together sometimes. She'd never let me live it down if I got it wrong!!!
Form what I've experienced, WWB from Walmart has more recoil than the Black HIlls HP I carried for a while. I guess my view on it is this:
If you're going to shoot a "defensive pistol" type competition, it should be shot with some degree of realism. While I don't expect to be shooting Gold Dots or Win Ranger every match, I do get alot of experience shooting a load that closely simulates the ammunition I carry. Then again, for some it's more of a shooting "game". Like some, I'm in it for personal reasons. The "competition" aspect is just a side benifit. Learning better handling, safety and shooting technique is at the top of my short list.
The social interaction is also a great reason to go. Where else can people from all walks of life gather for the sole purpose of defensive pistol shooting? That's a high caliber group, if you ask me!!
No offense meant to the reloaders who tailor their loads to their guns, by the way. It takes alot of R&D to get it right and people take pride in their work. I should have explained, this is my own personal view on ammo selection for matches.

Posted: Thu Jan 11, 2007 12:20 am
by age_ranger
I was in the office reading up on the IDPA rulebook when I spied this little phrase:
"IDPA is a shooting sport that uses practical equipment including full charge service ammunition to solve simulated "real world" self-defense scenarios."
To me, that says those sputtering rounds aren't cuttin' it. Just my 2 cents.
Posted: Thu Jan 11, 2007 12:57 am
by HighVelocity
simulated "real world" self-defense scenarios
That part always cracks me up.
Some of the stages I've shot could only be found on an episode of 24.