Power Factor for Matching Practice & Carry Ammo

[ar15barrels]

They still don't shoot the same. different acceleration profiles means different type of recoil behavior.

Of course they don't.
Look how different the energy is...

[broadside]

Of course they don't.

Look how different the energy is...

I didn't have my glasses and I didn't do the math myself, so I read it as 299 and 306.

[sigstroker]

The two different ammos the OP is talking about has a difference of about 50 ft lb just a smidge over 10%. It's probably not worth worrying about.

[socal m1 shooter]

Can't you just buy a box of 180's at the store and try it? There's nothing unusual about the Geco velocity so ordinary 180''s should be similar.

I may do that, time permitting.

[...] Power factor is NOT an energy calculation.

Favor, explain it like I am five years old. Why do competitors have interest in power factor? It is mainly to keep the playing field reasonably level?

The two different ammos the OP is talking about has a difference of about 50 ft lb just a smidge over 10%. It's probably not worth worrying about.

I wanted to order the ammo before I have time to make a range trip. I'm busy right now, but maybe a week or two would make no difference. Thanks for all the feedback, everyone...

[Chris Geiger]

My defensive rounds are 124 HST 9mm and they kick a little more than my practice ammo in my P365. I can't tell the difference in my larger xD 9 tactical because its extra weight. I do dry fire practice at home and get to the range once a month. Loading and unloading for dry fire wears the top two bullets so I shoot two defence rounds each time I go to the range and then shoot a box of 50 cheap ones. When I get home I top off the magazine with two new HST rounds at the bottom of the mag. This keeps my carry ammo fresh and I am used to the slight difference in feel.

[tanks]

...Favor, explain it like I am five years old. Why do competitors have interest in power factor? It is mainly to keep the playing field reasonably level?...

It is to do with scoring. Major power factor (165+) is scored differently than minor power factor (125+ - <165). Heavier bullets while keeping the same PF is softer shooting as well.

However, one can hit diminishing returns in bullet weight in that the heavier bullets slow down the slide going back and for some shooters that are quick on the trigger the slide ends up moving too slow for the next shot.

[ChuckDizzle]

I use Winchester white box jhp because it's almost as cheap as brass cased FMJ. I use it all.the time for practice and HD.

[ar15barrels]

The two different ammos the OP is talking about has a difference of about 50 ft lb just a smidge over 10%. It's probably not worth worrying about.

Actually, 15%.
And it will have different zeros or different impacts if the same zero is used.

[ar15barrels]

Why do competitors have interest in power factor? It is mainly to keep the playing field reasonably level?

Because the rules use power factor to separate the scoring system between major and minor class shooters.
Major gets a larger scoring area than minor.
The reason being that the more powerful loads are more difficult to shoot fast so to level the time-based playing field, minor class shooters have to hit a smaller target area than major class shooters.