Recoil question: 125gr vs 158gr in a 357 MAG

[duck911]

Hi all,

I've reloaded quite a bit for rifle but am still kinda new to handguns.

I have been shooting a mid-range load that I perceive as a extremely mild shooting:

12.5gr 2400
Hornady 158gr XTP

The local stores are out of 158gr's so I picked up 2 boxes of 125 gr this afternoon. I figured it'd be even milder, but to my surprise, I am reading about the more severe nature of shooting 125's.

I was thinking of a mild/mid range load like 14 or 15 grains of 2400 with the 125 XTP.

All other things being equal, what should I expect? I know I am adding powder but I am dropping bullet weight. I kind of figured it'd be a wash but I guess not?

thanks,

--Duck911

 

[LawofThirds]

You're getting a shorter recoil time with almost the same amount of recoil so it's a sharper jolt to the hand. The big difference is in the amount of noise and blast. Most people can't tell the difference between the recoil impulse but the increased noise and blast make it feel bigger than it is.

I like VihtaVuori N110 for JHP's between 110 and 158. You don't get very much smoke and it's nice and accurate at heavy loads without a lot of the flash.

 

[Border Hopper]

125 gr vs 158 gr

With a little (and I do mean little) math you can figure out the approximate value of the recoil. Very roughly, use the Power Factor.

PF= wt. of bullet in grains X velocity in fps
1000

So, 158 X 1075 divided by 1000
Vs. 125 X 1325 divided by 1000

(Those velocity figures are approximate, from the 3rd edition Hornady, your gun may not be the same, lawyer talk notwithstanding, both your loads look middle of the road.) Whew!!

And for instant gratification, the numbers are 170 and 166, rounded to the nearest whole number. That is just a number, but it gives you an idea that these two will have about the same Power Factor, and probably about the same recoil. That said, the actual recoil and blast factors are not being measured. The 125 grain load is above the sonic blast speed, so it may snort a little louder.

If you want Kinetic Energy, the formula is in the Speer reloading manuals.

 

[W.E.G.]

The "severity" depends on your powder choice, and how much you use.

Some powders flash (aka "muzzle blast) more than others.

A mild load with a powder other than the very fastest ones, will not be offensive.

Jack up the load to the book-max with 231, and I promise it will be fireball city.

 

[Jim Watson]

I did some work on that a few years ago.
With everything loaded to the same power factor and therefore having the same computed recoil (except for the little bit of difference in powder charge ejecta), I handed a gun loaded with 125, 158, or 195 grain bullets in near full charge .357s to other shooters in a blind test.

Everybody agreed that the heavier the bullet, the less the felt recoil, when shot slowly.

When shot in speed drills, there was no significant difference in time and score with 158 or 195 grain bullets, but the 125 was definitely harder to run. Was it the nature of the recoil or the louder muzzle blast? I dunno but the effect was real and repeatable for three shooters.

 

[gamestalker]

I just loaded a 158 gr. XTP for my .357 and actually noticed it was significantly more comfortable to shoot than the higher velocity 125 gr. XTP. I load with H110 and W296, full house magnum charges too.

 

[duck911]

Thanks guys!

I guess I will give these a shot (I bought them just to plink with anyway) but for what I use the gun for I want to stick with 158 and 180 grain anyway.

thanks!

--Duck911