Different bullet weight, same power factor

mcfoto · Apr 13, 2017

Newb question:

Freedom Munitions is offering 135 grain 9mm at the $.19 price that 115 usually sells for. I did the power factor math and the difference is negligible (129 vs. 132). A quick search of the googles says that the recoil will be similar but different: snap vs push. That describes what I feel when I shoot my son-in-laws 1911 in .45.

Can anyone help me with any other differences? Usage is USPSA competition. Once in the middle of a match, I discovered I'd accidentally bought 124 grain but didn't really feel any difference.

Certaindeaf · Apr 13, 2017

I shoot/load some heavier bullets in 9mm now and then and think they are softer shooting.. even when loaded fairly stout.
I don't compete in that and this is in a full-size, non-compensated gun.
Check out this forum.. they have a lot to say on what you are wondering..

Brian Enos - Competition Shooting & Reloading & Slide-Glide Gun Lube

bbbass · Apr 13, 2017

As long as you make power factor there shouldn't be any concern on your part. Because I have arthritis, I find the lighter bullets to be more comfortable. A younger guy, I don't think would notice much difference unless paying very close attention. Powder is actually reduced for bigger bullets in 9mm because of limited case dimensions. Look at velocity, that is why the PF is so close between the two.

As far as shooting 124gr, I think any factory ammo should make power factor but I'd have to do the math. I know I looked at it for some of the reload info listed in books and the 115gr reloads wouldn't make PF in IDPA.

How often is your club checking ballistics with chrono? Ours here was only once or twice a year.

mcfoto · Apr 13, 2017

bbbass said:
As long as you make power factor there shouldn't be any concern on your part. Because I have arthritis, I find the lighter bullets to be more comfortable. A younger guy, I don't think would notice much difference unless paying very close attention. Powder is actually reduced for bigger bullets in 9mm because of limited case dimensions. Look at velocity, that is why the PF is so close between the two.

As far as shooting 124gr, I think any factory ammo should make power factor but I'd have to do the math. I know I looked at it for some of the reload info listed in books and the 115gr reloads wouldn't make PF in IDPA.

How often is your club checking ballistics with chrono? Ours here was only once or twice a year.

Thanks for the response but I don't think you understand my concern: Freedom Munitions lists their velocity (I know this is a target or average) which is how I was able to calculate power factor. Both are above minimum with enough margin for error that I am not concerned with being legal. I shoot at Dundee and only have seen a chrono stage the major matches (Sectional or State championship) that I'm not competitive enough to shoot in anyway. I'm thinking as long as the cost is the same during this sale, it's worth the risk to buy half a case and try it. If I don't notice a difference, I can go back to 115 (usually cheaper). Just checking in case someone else had done this with not good results.

bbbass · Apr 13, 2017

I still don't understand your concern. I'm confused as to what you need advice on. I give up.

Crohnos01 · Apr 13, 2017

I am not sure if I am following either, but I think you are asking about recoil between the two loads. If so, it would likely be negligible. Physics dictates that there must be some, but I don't think it will be significant and you wouldn't notice it unless you are looking for it.

mcfoto · Apr 13, 2017

Crohnos01 said:
I am not sure if I am following either, but I think you are asking about recoil between the two loads. If so, it would likely be negligible. Physics dictates that there must be some, but I don't think it will be significant and you wouldn't notice it unless you are looking for it.

This is spot on. Thank you.

Most of chatter on the interwebs on the subject regards self-defense and stopping power. Just trying to translate it to competition application. Sorry to be confusing.

Certaindeaf · Apr 13, 2017

mcfoto said:
This is spot on. Thank you.

Most of chatter on the interwebs on the subject regards self-defense and stopping power. Just trying to translate it to competition application. Sorry to be confusing.

If you have a compensator and are running major power, the lighter bullets hold the sights down on target more than heavy bullets.. due to more powder/more blast working the comp.

Brian Enos - Competition Shooting & Reloading & Slide-Glide Gun Lube

jordanka16 · Apr 14, 2017

I shoot 124 instead of 115 for comp, recoil is less snappy and it's faster back on target. This is in production class with my CZ. I also reload though, so I have a little more control. But the 135s will not be worse, usually heavier bullet means more push and less snappy, which I find is easier to shoot.

bbbass · Apr 14, 2017

bbbass said:
I don't think would notice much difference unless paying very close attention. Powder is actually reduced for bigger bullets in 9mm because of limited case dimensions.

I think you didn't understood my reply.

You will not notice a difference. Buy a box locally and give it a try. Then you can order in bulk if the sale is still on.