Pressure or power?

[Mylhouse]

I'm just curious about something. As a reloader, I can reproduce the ballistics of +P factory ammo, with much lower pressures than +P, using the right powders. For example, I can push a 115 grain JHP at 1,300 fps from a Glock 26 (believe it or not) with Herco without going over 35,000 psi. Anyway, it seems to be common knowledge that a steady diet of +P ammo will wear out an auto much quicker than standard fodder. OK, that makes sense. But is it the PRESSURE of the round, or the POWER of the round that wears out a gun. Let's say I shoot a bunch of Corbon +P 115's rated at 1,250 fps. Is this any harder on my pistol than shooting my handloads that achieve the SAME EXACT VELOCITY, but with lower than SAAMI max pressures?

Thanks for any insight!

 

[444]

I am interested in hearing how you are measuring these presures. Don't get me wrong, I am not doubting you, just curious.

 

[Ben]

Well, I think the Cor-Bon 115's are actually rated at 1350. I'm not sure +P EXCEEDS SAAMI specs, but I think it's supposed to be "right there." I think +P+ is slightly above SAAMI specs though. I'm not sure if it's the SPEED of the bullet or the explosive pressure that causes the most wear on a gun. I'd be interested to know as well. It could just be the slide-to-frame battering that would wear more quickly for all I know.

Ben

 

[Mylhouse]

444,

Well, maybe the Herco load was a bad example. For THAT load, I was using load data from 1982, which was below the max pressure level on the CUP scale. I assumed that if it was below max CUP, then it probably was under the more current 35,000 psi standard pressure max. This may be wrong headed thinking, but I don't recall anyone having any problems with these loads 15-20 years ago.

With the new powders that are available today, you can get the old Norma ballistics (200 gr @ 1,200 fps) in 10mm WITHOUT EVEN COMING CLOSE to the 37,500 psi limit. More like around 25,000psi, believe it or not. So was it the PRESSURES that were beating up the Bren Ten and S&Ws, or was it the sheer POWER of the Norma load???

 

[Mylhouse]

Ben,

You may be right about the Corbon specs. However, the C-B 115's clocked 1,260 out of my Glock 26, while the Herco load clocked 1,360 out of the same pistol. The Herco load had absolutely NO primer smearing or other pressure signs, while the Corbon brass had significant primer smearing.

It appears Corbon doesn't use any "special" or "super efficient" powders...IMO they just seat the bullets VERY deep and apply a VERY strong crimp to raise pressures and velocity. Correct me if I'm wrong...

 

[KP95DAO]

Pressure, power, and wear and tear.

With too much pressure you can have a catastrophic failure. A burst bbl or cracked slide for instance.
With loads that are within pressure limits; but, are at the top in terms of kinentic energy produced, you will have accelerated wear.
You can achieve increased velocities within pressure limits by burning more powder at the same (or in some cases less) pressure. This is the idea behind the Hornady Light Magnum rounds.
I do much the same as you by loading 11grs of one of my blends behind a 115gr in 9mm. This allows me to get 1350fps out of my KP95s with no primer wipe.
The bottom line is if you want more you have to pay for it.