Power Factor And Terminal Ballistic Effects

[Chills1994]

Hi everybody,

With the new IDPA rules setting a power factor floor of 165 for CDP and ESR, and 125 for everything else, I was just wondering if there was a real world justification for this.

Are there any websites out there that deal with terminal ballistics and/or ballistic gelatin and bullet design effectiveness?

Off to a gun show.....

Thanks,

Brad

[ErikW]

I'm happy to provide a link,

International Wound Ballistics Association oops, it looks like they didn't renew their domain name. Here's another link:

http://www.firearmstactical.com/wound.htm

...but any discussion of wound ballistics on these forums will be shut down or removed.

Forum Guidelines

Edited May 7, 2005 by Erik Warren

[Ray_Z]

Eric

Tried your link I don't understand

[Nik Habicht]

Ray,

I'm not Erik, but here goes: This is primarily a forum for competitive shooters to talk about competition. While the occasional post about defensive shooting isn't prohibited, Brian is not interested in having pages and pages of them on the board ---- there are plenty of places for that discussion already on the web. A thread on terminal ballistics --- a subject on which everyone is sure to have an opinion --- will not live long and prosper here.......

[ErikW]

Unless the "terminal" part is impacting steel or punching through paper.

I suppose discussing the terminal effects of hunting bullets would be OK; there are many hunters here. And that's not an invitation to post about hunting two-legged, 200 pound "deer" with .40S&W Hydra-Shoks.

[Chills1994]

I read the forum guidelines, and it sounded like a post about defensive matters every once in a while would be tolerated.

My intent wasn't really to start a defensive shooting thread. It was more out of curiosity: "What was the rational behind setting a PF floor at this level? Is there more to it than just putting everyone on the same level?"

Thanks for your input and the link.

[Flexmoney]

I don't know why the power factor for minor is set at 125, but most/many store bought 9mm loads will make that power factor. I would have to guess that somebody was smart enough to figure out that, if they wanted shooters to show up to the matches, then (cheap) off-the-shelf ammo would need to qualify.

[Gun Geek]

I read the forum guidelines, and it sounded like a post about defensive matters every once in a while would be tolerated.

My intent wasn't really to start a defensive shooting thread.  It was more out of curiosity:  "What was the rational behind setting a PF floor at this level?  Is there more to it than just putting everyone on the same level?"

Thanks for your input and the link.

<{POST_SNAPBACK}>

I think you're well with-in bounds to ask this question. The answer is that the concept of pf was instituted to put everyone on a level playing field. The exact value of the pf is picked to model typical loads.

The 125 and 165 are just a hair lower than typical factory handgun loads. So by setting the parameters here, they insure that handloaders and guys buying factory are shooting similar stuff. The idea is that there is no big competitive advantage in handloading, so you don't have an "equipment race".

If you set the numbers higher, then only certian brands of ammo will make the number. Those will likely be higher priced, and may not be widely available (another race).

You might make an argument that the "defensive" part of IDPA would require higher PFs, but that would make the sport difficult and expensive to get into.

It is obvious that higher volocity rounds will likely do more damage in a shootout, but the practical implications in the game make them unreasonable to use in IDPA. IDPA makes several trade-offs to make the game more doable at the expense of rigid "correctness"

For example. I actually like to carry crossdraw (you can get to it with both hands) - but for saftey reasons, we don't do that in IDPA. Similar idea.

Are 125 and 165 in touch with reality? Depends on your reality, but they cover the most practical situations. ("I reject your reality and substitute my own")

[GRD]

Off the shelf Winchester white-box 230gr .45 makes 192. I think they could have upped the floor quite a bit.

- Gabe

[Duane Thomas]

For example. I actually like to carry crossdraw (you can get to it with both hands) - but for saftey reasons, we don't do that in IDPA.

Okay, I apologize for the thread drift, but there are techniques out there that allow you to draw from a strongside belt rig with either hand, as well. It's all in the knowing how.

[Nik Habicht]

For example. I actually like to carry crossdraw (you can get to it with both hands) - but for saftey reasons, we don't do that in IDPA.

Okay, I apologize for the thread drift, but there are techniques out there that allow you to draw from a strongside belt rig with either hand, as well. It's all in the knowing how.

<{POST_SNAPBACK}>

Of course being a skinny little fracker also helps ----- I'm pretty certain that I'm rotund enough so I can't get to a stronghand holstered gun with my weakhand........

Perhaps if I was willing to appendix carry, or to move the holster back towards my spine some more.....

Of course the point is really moot until I move.....

[redmercury2]

IT ORIGINALLY WAS CONCERNED with the impact on a ballistic pendelum,referring to IPSC.

[AikiDale]

The 165 PF came from measuring the .45 ACP fired through an Officers Model if I remember correctly and thus became the rational for the major power floor. A 230 grain projectile fired at 800 to 850 fps would be 184 to 195.5 pf. Typical loads for 5" 1911's.

[Chills1994]

OK, I understand now.

I thought, stretching here, that it might be based on so called one shot man stopper nonsense.

It all boils down to they're all games and have rules and need a level playing field. Yada Yada.

Thanks everyone.

You guys are all right.