Monday, August 30, 2010

Anybody ever put a can on an HK P7?

Oleg's wondering about the expense and difficulty of setting up a Jerry staplegun to take a suppressor.

From what I've heard about the difficulty of swapping barrels on those things, my first instinct is "pass", but someone out there may have better data.

14 comments:

Black Hat said...

I have data and I would say "PASS!"

The barrels are north of $250 when you can find 'em.

Caleb said...

I'm sure it theoretically could be done, but might be kind of cost prohibitive. Gray Guns are probably the best guys for HK work. I know that Bruce used to take the P7M13 and turn them in to longslide race guns, so I'd be willing to bet that he could pretty easily set up a P7 with a can. I just wouldn't want to see the bill for that work.

Ry Jones said...

Dr Dater of Gemtech has said it's one of his favorite pistols when suppressed; maybe he was pulling my leg.

Ancient Woodsman said...

It won't matter if he suppresses it or not...no shooting that pistol much until he turns the ammo around in the mag.

Ry Jones said...

tha backwards bullet is in homage to a similar error H&K made on a catalog cover.

Ry Jones said...

of course, I mean round, not bullet.

Mad Saint Jack said...

Buy a MK23.
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Because you suck and we hate you.

Dr. StrangeGun said...

Seems to me that someone could make a threaded adapter that has the threads at one end and a very thin metal sleeve that would cover the barrel all the way to the support at the back, use a high-strength composite (or a mid to low temp soldering alloy) to make the attachment permanent, enlarge the barrel opening in the slide, and fit a slightly larger interior diameter spring. For cost, the adapter could be two-part as well... use a pre-made steel tube instead of machining one.

Ed Foster said...

Not really familiar with the pistol, or particularly interested if it wasn't designed by John (PBHN) Browning. Pretty much anything worthwhile since, with the possible exception of the Petter trigger and the Tokarev feed system, has been lifted from one or another of his designs.

That being said, how hard would it be to open up the slide for a sleeve on the barrel?

The big problem would be timing the gas system, and not ripping off the head of the case. The Krauts have always had an inordinant love of a foolishly high cyclic rate (notice all those Glocks in .357SIG that are breaking in half across the front of the magazine well), to the point of producing weapons that are both uncomfortable and less controllable to shoot. Plus incredibly dirty (if you have to use chamber flutes to make it work, it ain't worth it).

You know what might do a decent job with subsonic 9mm's? An old Astra 600. Don't laugh.

Remachine that disassembly bushing up front to mount a can, fixed barrel, massive slide, ergonomics of a railroad tie but who's looking for svelte with a silenced pistol?

Plus I suppose there are those who would want a throwaway that couldn't be traced to anything more recent than the Condor Legion, and I see a $300 to $400 Astra without paper trail at least once or twice a year.

I can only imagine how many of those critters came back in dufflebags in 1945, and Mom wants to get rid of the damned thing now that Dad's passed on, etc.

As subtle as a sledgehammer, but everyone of them I've seen was well fitted, with seemingly decent heat treatment.

Tam said...

"The big problem would be timing the gas system, and not ripping off the head of the case."

Actually, that probably wouldn't be that much of a worry on the P7, since the gas is just retarding the slide travel, rather than driving it, with the port back there right in front of the chamber.

Ed Foster said...

Wellll, maybee, but.....

Much longer pressure peak with a can, although the flutes might ameliorate that. Or they might just shred the case/rip off the rim with the pulse holding the brass at max obturation in said flutes for several times as long, particularly with the standard H&K massively fouled chamber.

The guy to run it by would be Mack Qwinn, up at MGI Military in Maine. He may have more suppressor/silencer time than the rest of the human race combined, and has more firearms patents actually out there working in the field than anybody since JMB.

Of course, his opinion of the G-3 system, of which this is a pretty obvious single hand variant, is even lower than mine. It's one of those wildly over engineered things the Germans can sometimes get silly over.

Hard to figure the Krauts. Brilliant ergonomics and shitty metallurgy. Expect to destroy a sawblade every 3 cuts on their horrible toolsteel, which has carbon nodules and alloy hardspots every few millimeters.

Suprisingly, the Japanese are almost as bad in that field. If you want good toolsteel, you have to buy American (like the Japanese) or Swedish (like the Germans).

The Germans have gradual "type improvement" engineering skills at least as good as the Japanese, and were the standard by which good chemical engineering was measured from the late 19th century until the 1960's, but they can't design a good military/police type smallarm unless they're desperate and losing a war.

Even then they fall flat on their face if it's not a straight blowback or a conventional gas operated rotating bolt.

A delayed blowback with nowhere near enough slide mass, balanced out with the typical H & K cheater flutes and dependent on fresh and supple new brass to make it function at all. Mark me underwhelmed :-(

I reverse engineered H&K's MG4 machinegun belt feed a couple of years ago for Mack Qwinn, when we were doing the switch barrel upper/quick change magwell lower. The actual feed tray dimensions and geometry were determined by multi-million round empirical design, so I felt comfortable letting H&K do all the development work for me on top.

But the pawl/ratchet/multicam/zillion spring/auxiliary coffee grinder function section underneath was what my Bavarian Great-Uncle would have called, if you'll forgive the language, einen farflugtig kukuswerke.

It took me a week to get a single spring, single cam and cartridge lifter setup working, without all the silly spagetti H&K had in there.

I didn't do anything original, just applied some common sense and standard American firearms practices. Without exaggeration, I could think of at least 20 guys or gals I've worked with at Colt's or S&W who could have done as well and (almost) as quickly.

Something about lipstick on a pig. I suspect the Bundeswehr has been going downhill since they traded their FN's for G-3's. Maybe they should scrap everything except KSK, GSG-9 and the Gebirgsjaegeren, and let the rest spend their time planting trees.

Anonymous said...

On the other hand, the MG-3/MG-42 is still the standard by which all GPMG's are measured, 70 years later.

Ed Foster said...

Point conceded, but see the above concerning conventional weaponry vs. teutonic flights of fancy.

Remember also that the MG-34 it replaced was wildly over engineered, rediculously expensive to produce, and embarassingly unreliable. The MG-42 was specifically designed to address the -34's shortcomings.

People don't usually replace their standard MG only a few years after it's introduction without serious reason, and doing it under the pressure of fighting a rather large war must have engendered a certain sense of urgency.

The MG-42 is proof that, after enough machine gun crews ended up on the wrong end of a grenade or bayonet, even the bureaucrats have to listen to the poor buggers who actually use the things.

The -42, despite the rediculous cyclic rate of it's early models and their poor sustained rate of fire, was and is a truly good weapon, and the later "tweaked" E-4version of it's bastard son the M-60 is even better, now that bolt disassembly problems, flimsy sheet metal, and feed tray geometry have been addressed.

The -60's gas system is simpler than it's parent's and the belt feed runs with only a single pawl, all good things. The fewer moving parts, the fewer things to go wrong.

But I would still give top dollar for a GPMG to the M-240/FN MAG, which is essentially a BAR turned upside down with an MG-42 belt feed attached.

The best of all worlds, if you don't mind lugging a few extra pounds. The bugger just won't quit,eats an amount of dust that would choke a -42 or -60, and little things like getting dropped off the occasional cliff don't seem to bother it at all.

With a mean rate of 26,000 rounds between failures there's nothing short of a water cooled M-1919 that could concievably outlast it.

Again, not knocking the MG-42/M-60 family, but ruggedness is the primary virtue in a GPMG, and the -42 is good, but the MAG is better.

Michael in CT said...

For what it's worth, according to Massad Ayoob, the P7 can have issues with the light 90 grain loads and the various exotics such as Glaser and Magsafe and become other then it's normally 99.999% reliable self. I've fired 5000+ rounds through my P7M8 and aside from a fluke failure to fire which may have been my fault, it has been 100% reliable with 115gr, 115 +P, 124gr and 124gr +P. I also know someone who fires Wolf Steel case through his M13 and his is totally reliable as well.
Not sure whay one would go to all that trouble, it'd be easier and cheaper to buy a used Glock and put a can on that.