[MikeO]

Which load is harder on a gun, accelerates wear, reduces the service life of a weapon more?

A 124/9 at 1120 fps but at +P pressure (EFMJ), or a 124/9 at 1150 fps but at std pressure (Gold Dot)?

Too close to call?

What's harder on the gun, the higher pressure or the higher velocity? How and why?

If two loads have the same power factor, say a std pressure 147 at 995 fps and a +P 124 at 1180 fps, why is the higher pressure load harder on the gun (if it is)?

What has more effect, if any, on how hard the gun unlocks, how fast/hard the slide hits the frame, etc, the pressure or the velocity of the exiting bullet? If pressure doesn't effect any of that, how does it stress the gun?

If two loads of the same weight have the same velocity, but different pressures, do they have the same impulse, recoil velocity, recoil energy, etc?

Just wondering how those interact.

Probably didn't ask it very clearly, hoping ya can figure out what I'm getting at?

 

[Charlie Petty]

I don't have time to write a book Mike and all of your posts are somewhat connected.

I dislike +P and detest +P+ and have never seen anything that really convineced me that there was any benefit. The lone exception- from a lot of testing in 96- was the .38 Special +P and that largely because nobody bothers to work on a good standard pressure load.

There is a direct and absolute relationship between pressure and velocity as long as we are talking about the same cartridge, powder and bullet weight. So if somebody pushes a 124 at 1200 and another only does 1150 that one will have lower pressure.

Most of the time the velocity of the recoiling slide is the concern and springs or buffers do little to help in that.

I would expand Bill's comment to almost any autopistol just because there is little gain. You're right about NATO being generally higher presure although some of the newer powders appear to be able to make the desired velocity at slightly lower pressure. The hottest 9mm I know of is the British 2Z (two zed) but unless they've changed their pistol is still the P-35. Go figure.

Much as I hate to say this a lot of the kBs are traced to reloads but I don't hear of many failures with the 40 in other guns compared to the freqency in Glocks. And problems in 9x19 are really rare. I think part of that is the fact that it is a tapered case and pretty strong at the web.

I am also more convinced than ever that the majority of people who report disasters are passing on hearsay with little evidence.

I just saw a photo on another board of a purported kB that was an absolute fake. You need to employ a little critical thinking and it helps to know something about the gun allegedly involved but all the sheeple immediately condemned the maker and vowed to rid themselves of the offending gun. One guy correctily identified the fraud but everyone simply ignored him because he wasn't saying what they wanted to hear. This is why I don't go to other boards...

 

[MikeO]

Thanks.

Bought a bunch of the EFMJ stuff a while back, the 124/9 +P and 200/45 +P. Pretty mild to shoot, even though they are +P loads.

They don't seem to kick the slide back any harder/faster than std pressure loads at the same weight/velocity, was wondering where the extra pressure was going and what it was doing.

 

[Charlie Petty]

Aw Mike... do you really have adequately calibrated paws?

I think that if you were able to compare the recoil velocities of the slides with different loads you'd see where the pressure went.

My experience with the 45 EFMJ is that it's pretty hot... so is the new HST.

 

[MikeO]

The 124/9 +P EFMJ averaged 1105 fps, The std 124 HS did 1135 fps, the std 124 GD did 1150, the std 124 HST 1157.

Wondered if the 9x19 EFMJ +P was really any harder on my gun (doesn't feel like it).

The 200/45 +P EFMJ at 1000 fps was noticeably milder than the 200/45 +P GDs I had at 1090 fps. Just a slow lot f EFMJ?

The 230/45 +P HST is a bruiser; waaaay too hot for me! Averaged 982 fps from a 5 inch 1911!