Bullet weight vs. recoil 9mm?

[TH3180]

I got to thinking on my way home. How does bullet weight affect recoil? I shot my 1st IPSC match last Thursday. The name of the game is speed and accuracy. The faster I can get the sights back on the target the better. I am shooting 115g bullets right now. The only reason I am shooting 115g is because when I bought my gun that's what they threw in for free ammo. When I started reloading not to long ago I just stuck with the 115g. I know my options are 115g, 124g and 147g. Am I going to get less recoil from a 147g compared to a 115g or is the other way around? For all I know bullet weight does affected it at all and I am barking up the wrong tree here. Any help you folks can give would be great. If I change bullet weights I won't have the time to work up new loads before the end of the season which is the 1st week in April, but it would give me something to do over the summer. I don't think it matters but I am shooting a Gen3 G17.
Thanks
Tim

 

[rcmodel]

Plug in all the numbers here and see what it says:
http://www.handloads.com/calc/recoil.asp

rc

 

[ny32182]

If you are going for a specific "power factor", which is a pure momentum calculation, you will generally get less recoil with the heavier bullet at the same power factor. This is why the vast majority of top end competetive shooters are using 147gr.

 

[mokin]

I bought a bunch of 147 grain Speer FMJs on sale and expimented with them quite a bit. I pretty much started at the low end of the published data and worked up to the max. I found that I liked a load in the uppper mid range best. There was definitely more recoil than with the 124 grain loads I shoot more often but through a Browning Hi Power it was still quite managable. I did use them at a three gun match and found them to be accurate and even at less than full power have enough oomph to knock down steel targets (with one shot) at the furthest distance we had to shoot them. As opposed to having to hit a steel popper two or three times as I have had to do on occasion with 115 grain bullets. Sorry for the long post but I guess what I learned is:

1. There is more recoil.

2. You don't have to load full power for matches.

3. If you have the time and resources to experiment, you can find a sweet spot and get the best of both worlds.

 

[ny32182]

What velocities are you working at?

In IDPA SSP/ESP, you have to make "power factor" of 125k or more. Weight times velocity > 125,000. I think, but am not sure that this exact same rule applies to minor PF shooters in USPSA; I'm sure someone will correct that if it is wrong.

In my case, my original match load was 115gr bullet at 1107fps = 127305 power factor.

I switched to a 147gr at 879fps = 129213 power factor. So there is actually a bigger "safety margin" over 125k with the 147gr load, yet it recoils notably less than the 115gr load.

Now I've seen people have problems knocking down some steel targets in matches, but never had an issue with it myself, because I always shoot legal ammo. I can only conclude that people having trouble knocking over steel are not shooting legal ammo. I would say if there is a piece of steel that won't go down with a single good "COM" hit from a load making power factor, the target needs to be adjusted, and more than one or two people will have an issue with it. (I'm not talking about people who double tap it to make it go down faster).

 

[1SOW]

Mr. 32182:

I think, but am not sure that this exact same rule applies to minor PF shooters in USPSA; I'm sure someone will correct that if it is wrong.

In USPSA: bullet wgt X velocity / 1000= PF The 125 power factor is the minimum for "Production Class" and "minor" loads. 125gr bullet X 1000' per sec / 1000= 125 PF

In my experience, heavier bullets at the same PF, have less recoil/flip than the lighter bullets.

Many shooters prefer the 124/125 gr bullets, as do I.

 

[TH3180]

I should have been more clear. These matches are not sanctioned by IPSC. They are using there rules as a guide line and that kind of stage setup. There rules for production class are no optics, no ported barrels/compensaters and 10 round max in mags. I'm shooting minor because I am shooting a 9mm. It's the poor man version of IPSC.

 

[1SOW]

They are using there rules as a guide line and that kind of stage setup. There rules for production class are no optics, no ported barrels/compensaters and 10 round max in mags. I'm shooting minor because I am shooting a 9mm. It's the poor man version of IPSC.

The bullet wgt vs recoil issue is based on like PF/loads/impact-I guess. If you load one totally different than the other then all bets are off.

 

[918v]

147's loaded with fast burning powders have less recoil than 124's loaded with slow burning powders. Somewhere there is a happy medium, where either load will have a similar feeling recoil, but you have to consider more than bullet weight alone to make that determination.

 

[RandyP]

Basic Newtononian physics apply. For every action there is an equal and opposite reaction. It takes more force to move a heavier object at the same speed as a lighter object.

IMHO the difference is in 'perceived' recoil. At least for me, heavier bullets have more of a thump, lighter ones more like a snap. The 'thump' ones seem to go back on target quicker for me. Well, it makes sense to me anyway - lol

 

[ny32182]

The aren't being loaded to the same velocity; they are being loaded to the same momentum. Thus velocity of the heavier one is lower.

 

[cheygriz]

I suppose you could measure differences with test equipment, or feel it in subcompact guns, but in my 9MM weapons, (Glock17, SIG 226 and 239, Beretta 92, P-38, Luger, and Sterling carbine) I can't really tell from the recoil if I've loaded 100 grain Hirtenbergers, IMI 124 submachinegun ammo, 115 standard pressure, 127 +P+ Rangers or 147 grainers. None of them "kick" enough to notice.

 

[ny32182]

There is an obvious recoil difference between hot 124g +P defensive ammo and a competetive power factor 147gr load when fired back to back.

 

[Shoot66]

If in doubt, check out the Brian Enos webpage.
For me: The lighter the bullet the snappier the rise, the faster the return to the target.

 

[TH3180]

I shot 147g at the match tonight. I don't know if I really noticed a differance in recoil or not. I do know my over all shooting was better tonight. Could have been the bullets, could have been that I didn't have the 1st time gitters. Who knows? I plan on doing a lot more shooting with both and I will see what I come up with. Stuff like this is why I got into reloading, it's a lot of fun to me.

 

[jmorris]

Math aside, the best feeling (soft) "minor" 9mm load I have found is:

Berry's 147 RN
3.1 VV N310
1.160" OAL

You can save a few pennys and get close to that load by using 3.2 of titegroup, same everything else.

 

[jmorris]

Perfect double