.357 Magnum +P?

[priv8ter]

Hi. Working on a tip from Mr. Jim March, I was cruising arounf the Georgia Arms Website. They have two loads that interest me...a 125gr JHP, and their 158gr JHP 'Deer Stopper' load. Both these loads are listed as +P.

Now, not yet being a reloader myself, my understanding of +P ammo, is that it comes closer to the SAAMI(may have goofed that up) guidelines for chamber pressure, and may not be safe in older guns.

In my case, I think the 125gr .357+P would be a nasty beastie out of my SP-101. I have heard that SP-101's are supposed to be the toughest of the smaller frame .357's...anyone have any experience with the G.A.'s load in an SP-101? I wouldn't be shooting this all the time...I don't think my wrists could handle it. But think of the fireball...

As for the 158gr 'Deer Stopper'...I got a new marlin 1894C for Christmas, and I think out of that 16" barrel, it could ruin some poor Bambi's day. But...I would ahte to ruin my brand new toy...er, tool, by pushing it to far. I would think that since the 1894 also comes in 30-30, I wouldn't need to worry about chamber pressure, but I've been wrong before.

If anyone has any data or experience, I'd sure appretiate it.

Greg

 

[Sean Smith]

There is no such thing as +P in .357 Magnum. Alot of companies mark their stuff +P, even when SAAMI doesn't have a +P spec for that caliber, as a marketing gimmick.

Now, not yet being a reloader myself, my understanding of +P ammo, is that it comes closer to the SAAMI(may have goofed that up) guidelines for chamber pressure, and may not be safe in older guns.

Not exactly. Each caliber has a standard maximum pressure specified by SAAMI. "+P" is a separate SAAMI specification for a higher-than-standard maximum pressure for a given cartridge. But most cartridges don't have a +P spec at all.

Incidentally, Gegorgia Arms should be able to get the 158gr @ 1,250 ft/sec from a 6" barrel for their supposedly "+P" ammo by staying within the standard SAAMI pressure spec for .357 Magnum. But since they are marking their stuff +P, and there is no such thing as a +P spec for .357 Magnum, for all we know they are completely blowing off the SAAMI pressure spec and using some stupid, dangerous overload.

More likely they think it is just a "cool" marketing ploy and are loading their ammo to standard SAAMI pressures for .357 Magnum. I personally consider the whole "fake +P" thing a rather moronic practice, if not downright dishonest.

 

[HankB]

AFAIK, there is no official "+P" designation for .357 Magnum.

Now, some cartridges like 9mm Parabellum have a "+P" level of, IIRC, 38,500 PSI, which is just a bit higher than standard pressure, which is, again IIRC, 35,000 psi. Manufacturers loading above this mark their super hot ammo "+P+" even though there's no official SAAMI designation. Boxes of "+P+" 9mm ammo I've seen claim the pressures are up to "40,000 CUP" which is a bit hard to relate to psi figures . . . I'd guess 40,000 CUP corresponds to something above 40,000 PSI.

Maybe Georgia Arms' unofficial "+P" .357 designation means that the loads in question meet the OLD pressure standards, which SAAMI lowered in response to small and medium frame .357's being marketed which didn't stand up to continued use of "real" Magnum ammo.

 

[Dave T]

Most factory 158g 357 Mag loads will do 1200-1250 fps in a 6" barrel. Georga Arms is doing a bit of marketing hype, that's all it is.

 

[Snowdog]

Didn't Georgia Arms once load a 158gr Gold Dot at 1450 FPS?
I remember such a load offered in their "Shear Power Plus" line a while back, but can't find it on their website now.

I was going to defend G-A by pointing out a possible misnomer implying use of the above ammunition only in modern revolvers of decent condition... but now I can't be so sure. What I just saw at their website indeed did look more like a marketing ploy than a mistake.

Nonetheless, they do make quality ammunition.

 

[Standing Wolf]

I personally consider the whole "fake +P" thing a rather moronic practice, if not downright dishonest.

I'll concur with that—and skip doing business with companies that can't trouble themselves to be square with shooters.

Years ago, I hot-loaded some .357 magnum rounds, only to realize it made much more sense to switch to standard duty .44 magnum rounds. I've considered hot-loading some .357 magnum rounds for my pre-agreement Smith & Wesson model 60 carry gun, but again, have talked myself out of it: if factory rounds aren't good enough, I probably ought to start packing a bigger caliber—and anyway, I've got a hunch the little J frame wasn't meant for hot loads.

 

[BluesBear]

What's next? .454 Casull +P? .500 S&W +P+ ?