Can I run +P ammo in my Mark III?

The MkIII can handle +p fine. Blast away.

 

I have done it (without problem) but heard/read it wasn't recommended. Had been considering a .40 (then converting it to 9mm) so it could handle hotter loads. So...... that's not necessary after all?


Sent from my iPhone using Tapatalk

 

OK.... update time:

Have no idea where I heard/read it would void your warranty (or any idea how they would know) but this is what my manual said:

I happened to be digging around on that shelf for another reason...... In flipping through the pages, I didn't see a date but you can tell by the format of the web address (inside cover, on left), that mine is way too new to be anything other than a MkIII. Anyway, Browning advises against it in their manual but there is no "don't do it as it could kill you" type of warning. There is also no warranty mention.

Based on this, I would now say..... "Browning/FNH say don't but it seems as though the weapon can handle it. Happy shooting."


Sent from my iPhone using Tapatalk

 

If you want to run +P ammo, then you need to use an 18.5# recoil spring. This was the late, great Stephen Camp's choice. Wolff has the springs.

 

Will just the spring be enough? Isn't the issue the frame being weaker?

 

If you're interested in SD ammo and considering +P, I suggest reading https://forums.1911forum.com/showthread.php?t=498746&highlight=defense

Jäger, the initial respondent to the question, has a great fund of knowledge.

 

If you have one of the newer (post 1994 I think?) cast frame Hi powers, you should be fine with +P. When FN/Browning rolled out the .40 cal Hi Powers back in the day, they had problems with frame cracks on the older style forged frames. Going to a cast frame is what supposedly solved the problem, so they ended up using the newer .40 frame for the 9mm models as well. If that frame can handle the .40, it can definitely handle 9mm +P, though I still prefer to shoot std pressure Ammo out of all my guns because it is less wear and tear on the firearm. If you look at the bottom of your grip frame around the mag well, if you see ridges you have a cast frame. If it is smooth you have a forged frame.

I know it sounds counterintuitive, you'd think the forged frames would be stronger than cast, but with the HP at least, it appears the opposite is true.

 

Mark, Yes you can, and I have. A topic I routinely see discussed on firearms enthusiast forums, is use of 9MM NATO, +P, or God Forbid +P+, in this or that 9MM pistol. People seem most concerned about use of such ammo in the, apparently delicate, little Hi Power. I've only owned Hi Powers since the '60s,i.e., INGLIS, Pre T-Series, multiple T and C-Series, a MKII, multiple MKIIIs, etc. Carried the Hi Power, used it in matches, used it for the 5 1/2 day API 250 class at Gunsite,etc. As yet, I've not been unable to detect any accelerated wear or damage to my Hi Powers due to type of ammunition used. In all those years of Hi Power use I've only had one part break, a firing pin stop on a MKIII. I've maintained a small stock of Hi Power parts for many years, and had hoped to use more of them. No luck yet, but I'll keep everybody posted

 

You make a very valid point, Rock. The HP has been for decades one of the most widely issued military sidearms among NATO countries, and 9mm NATO is loaded at or near +P pressures. I'm really not sure where the issue of +P being an issue for the HP came from. I can only assume it's mostly been with used/abused military pistols that were not properly maintained. Many of those pistols are decades old. I've read that there were even still some Inglis HP's in service with the British military before they began their transition to the Glock 17.

 

Looking for some input here. Can I run +P ammo in my Mark III ...

For the 9mm I do not think +P or +P+ is necessary. Hollow points is significantly better than hardball.

Putting good hits on target is better than marginal hits or misses.

 

For the 9mm I do not think +P or +P+ is necessary.

I agree. I'm also of the frame of mind that hollow point technology has improved to where +P really isn't necessary anymore in ensure reliable expansion. That being said, Federal 9BPLE will always have a special place on my ammo shelf.

 

Consider using a flat bottom firing pin stop, which was the original design.
It eliminates the mechanical advantage of the radius stop- which retards slide velocity.

 

I run a flat bottom firing pin spring, 18.5 lb main spring, and a 28 lb hammer spring in my setups.

What I have found interesting that it has cycled and extracted perfectly with all ammo, except federal aluminum case. Roughly 90% of the time, the slide will travel far enough to extract the round, but the slide will stop on the back of the round without stripping it off the magazine. Switching to the factory firing pin stop allows it to function perfectly, but with weak extraction.

 

I was just thinking, if we could buy factory 9MM ammunition for our Hi Powers loaded to .380 minus-P levels, just think how long our Hi Powers would last. Say something like 90 grains at 650 FPS. After all, with today's advanced bullet technology, high velocity isn't really needed

 

I totally agree. Standard pressure Federal HST 9MM, for example, even in a 3.5 inch barrel, expands to a little over .60. In a Hi Power, that load should be, at the very least, as good or better.

 

There is absolutely no reason to run +P ammo. It is exactly like believing that if you pump premium grade high octane gasoline into a car that was designed to run on regular gas will somehow make it go faster. If you can place the round where it needs to go +P isn't going to make them any "deader".

 

+P 9mm ammo like Gold Dots will expand more but not necessarily penetrate any more than the standard-pressure version. The advise is usually the same regardless of what pistol you use. Put a box or two of the +P through your pistol just to be sure it works fine with it, then carry it with +P but use standard pressure ammo for all of your practice sessions. When my +P carry ammo starts to get beaten up from repeated cycling through actions I usually just burn it up through my Glock 19, for not only will handle it just fine but also I couldn't care less if it hurts it.

 

I agree that the later Hi Powers will handle +P ammo but no longer use it in mine because Browning says not to . The gunsmiths at Cylinder and Slide agree. The BHP's very heavy hammer spring's weight serves to retard slide velocity for the light weight slide. Cutting the hammer spring or using a lower weight one would be a poor idea if +P or +p+ ammo is used. Of course, everybody here knows this fact, but I wanted to state it for general information.