Mouse Guns Get Even Mousier

[Stephanie B]

A 4.6x30mm (https://www.shootingtimes.com/editorial/fiocchi-46x30mm-hyperformance-defense-round/468336)?

What’s next, a 3mm? Or a 0.9mm, for all of those crappily edited news stories?

[Caballoflaco]

It was developed by H&K back in the late 90’s for their PDW program and is in current use with some specialized US military folks in the MP7. The only reason it hasn’t been available publicly is that zee Germans said that gun and it’s cartridge weren’t meant for civilian consumption.

https://www.heckler-koch.com/en/products/military/submachine-guns/mp7a1/mp7a1/overview.html

[hiro]

Hot on the heels of the M&P 5.7 thread, seems this (https://pistol-forum.com/showthread.php?4338-Small-Caliber-PDW-s-FN-5-7-mm-HK-4-6-mm) is my favourite thread to quote

[TGS]

A 4.6x30mm (https://www.shootingtimes.com/editorial/fiocchi-46x30mm-hyperformance-defense-round/468336)?

What’s next, a 3mm? Or a 0.9mm, for all of those crappily edited news stories?

You won't see 4.6 in a pistol...especially a mouse gun.

Similar to how FN developed the P90 and Five-seveN pair, HK developed the MP7 and UCP pair (Ultimate Combat Pistol). The UCP was cancelled in development as HK stated that they couldn't get satisfactory ballistics in pistol length...I seem to remember there being a problem with accelerated erosion in pistol length barrels, as well.

[the Schwartz]

A 4.6x30mm (https://www.shootingtimes.com/editorial/fiocchi-46x30mm-hyperformance-defense-round/468336)?

What’s next, a 3mm? Or a 0.9mm, for all of those crappily edited news stories?

Pistols (albeit fairly large ones that would be problematic to conceal) in 4.6x30 have been available since late 2021 according to this article—

https://www.gunsweek.com/en/pistols/news/cmmg-four-six-worlds-first-46x30mm-civilian-firearm

A barrel length of 8'' seems to be the minimum viable length:

https://cmmg.com/pistol-banshee-mk4-4-6x30mm-8

[SCCY Marshal]

What’s next, a 3mm? Or a 0.9mm, for all of those crappily edited news stories?

I've got a pack of 3mm in my bag, 2mm in my pocket, and a 0.9mm clipped to my legal pad cover.

[Navin Johnson]

Seems like the 22 lunacy in the J frame thread has died down….. hopefully this won’t reignite it

[MandoWookie]

It was developed by H&K back in the late 90’s for their PDW program and is in current use with some specialized US military folks in the MP7. The only reason it hasn’t been available publicly is that zee Germans said that gun and it’s cartridge weren’t meant for civilian consumption.

https://www.heckler-koch.com/en/products/military/submachine-guns/mp7a1/mp7a1/overview.html

It's actually been intermittently available on the civilian market for years( prior to 2020 ammo drought at least) just no guns to shoot it in.
SG Ammo used to have it occasionally, I guess as overruns from police contracts.
Only users would be Class 3 dealers with post sample MP7s, but it was out there.
Edit to add: Similar to how 9x39mm showed up for sale through Wolf long before anybody had any guns in the US that could shoot it.

[Stephanie B]

It was developed by H&K back in the late 90’s for their PDW program and is in current use with some specialized US military folks in the MP7. The only reason it hasn’t been available publicly is that zee Germans said that gun and it’s cartridge weren’t meant for civilian consumption.

Well, we all know their unofficial motto:

100507

[jh9]

Sooner or later, modern materials, propellants, stupid high chamber pressures, whatever, it seems likely there's going to be a pistol-sized pistol capable of breaking the 2000-2300fps threshold. Does it really matter if the permanent crush cavity is only 3mm in diameter if the rifle-type-wounding shredded tissue is considerably larger? Legitimate question.

Rapid erosion of the chamber doesn't honestly seem like a problem for something with a drop-in replacement barrel. Getting rifle ballistics out of a pistol would be a pretty big win that would justify a whole lot of drawbacks.

[Nephrology]

Sooner or later, modern materials, propellants, stupid high chamber pressures, whatever, it seems likely there's going to be a pistol-sized pistol capable of breaking the 2000-2300fps threshold. Does it really matter if the permanent crush cavity is only 3mm in diameter if the rifle-type-wounding shredded tissue is considerably larger? Legitimate question.

Rapid erosion of the chamber doesn't honestly seem like a problem for something with a drop-in replacement barrel. Getting rifle ballistics out of a pistol would be a pretty big win that would justify a whole lot of drawbacks.

I am no physicist but every rxn = equal/opposite rxn.

Between limitations of barrel length and acceptable recoil characteristics in an actual (not just ATF defined) pistol I don't think we will get rifle like injuries from a handgun. Just sort of the worst of both worlds.

maybe I'll be proven wrong. Just not sure how you can get away from the recoil/energy required to propel a cartridge fast enough to do so. but again, not a physicist nor an engineer.

[GearFondler]

I am no physicist but every rxn = equal/opposite rxn.

Between limitations of barrel length and acceptable recoil characteristics in an actual (not just ATF defined) pistol I don't think we will get rifle like injuries from a handgun. Just sort of the worst of both worlds.

maybe I'll be proven wrong. Just not sure how you can get away from the recoil/energy required to propel a cartridge fast enough to do so. but again, not a physicist nor an engineer.Maybe if you build it on the Desert Eagle frame... It's not like it can get much more impractical, lol.

[TGS]

Sooner or later, modern materials, propellants, stupid high chamber pressures, whatever, it seems likely there's going to be a pistol-sized pistol capable of breaking the 2000-2300fps threshold. Does it really matter if the permanent crush cavity is only 3mm in diameter if the rifle-type-wounding shredded tissue is considerably larger? Legitimate question.

Rapid erosion of the chamber doesn't honestly seem like a problem for something with a drop-in replacement barrel. Getting rifle ballistics out of a pistol would be a pretty big win that would justify a whole lot of drawbacks.

IIRC, the barrel erosion was pretty severe. It wasn't something as workable as 10,000 rounds vs a 9mm barrel that can usually go 50,000+ rounds at a minimum.

IIRC, it was a thousand rounds or less...again, don't quote me on the number, but it was something pretty extreme....and that was with 4.6x30mm, which does not give us rifle like ballistics. So, if you used emergent composite case technology and novel powders to get us a rifle-like ballistics version of the 4.6 or 5.7, the erosion would be even worse.

ETA: I think it may have been the late Jim Schatz (PM for HK) over at HKPRO that discussed it. That was a long time ago, though, so I wish I could find it directly to give you.

[JRB]

Tommybuilt Tactical has made ~20 or so semiauto MP7's from parts kits. They sell for $40k+.

So 4.6x30 is not *EXCLUSIVELY* the realm of a few HK-initiated SOT's and a few spicy secret squirrel mil units anymore.


IIRC, the barrel erosion was pretty severe. It wasn't something as workable as 10,000 rounds vs a 9mm barrel that can usually go 50,000+ rounds at a minimum.

IIRC, it was a thousand rounds or less...again, don't quote me on the number, but it was something pretty extreme....and that was with 4.6x30mm, which does not give us rifle like ballistics. So, if you used emergent composite case technology and novel powders to get us a rifle-like ballistics version of the 4.6 or 5.7, the erosion would be even worse.

ETA: I think it may have been the late Jim Schatz (PM for HK) over at HKPRO that discussed it. That was a long time ago, though, so I wish I could find it directly to give you.


https://www.hkpro.com/threads/hk-ucp.126642/

Wasn't barrel wear, it was lockup wear because the forces involved really beat the crap out of the gun apparently. But instead of HK evolving that idea and solving that problem with metallurgy, the relatively poor performance out of pistol length barrels is what apparently killed the UCP once and for all:

https://en.wikipedia.org/wiki/Heckler_%26_Koch_MP7#Heckler_&_Koch_UCP

[the Schwartz]

Sooner or later, modern materials, propellants, stupid high chamber pressures, whatever, it seems likely there's going to be a pistol-sized pistol capable of breaking the 2000-2300fps threshold. Does it really matter if the permanent crush cavity is only 3mm in diameter if the rifle-type-wounding shredded tissue is considerably larger? Legitimate question.

Rapid erosion of the chamber doesn't honestly seem like a problem for something with a drop-in replacement barrel. Getting rifle ballistics out of a pistol would be a pretty big win that would justify a whole lot of drawbacks.

What you suggest has been attempted before, most notably with the .224BOZ. Although the .224BOZ proved capable of firing a 40-grain steel core projectile at 2,300 fps from a 5'' barrel, excessive erosion at the leade of the bore was not the only factor that led to its demise. Enormous bolt face thrust resulted in failures/cracking that required special hardening processes to accommodate.

The forces resulting from the increased pressures required for shortened runways to match the performance obtained in longer runways at lower pressures will always play havoc with smaller guns (pistols) by battering their engagement surfaces to death.

On the other hand, even if those mechanical consequences could be mitigated to the point at which the concept would become feasible and attractive enough to pursue, would you really want to fire a realistically concealable pistol (5'' barrel or less, weighing 25 - 32 ounces) that was capable of firing a standard weight (120 - 180 grains) service rifle-caliber projectile at >>2,300 fps?

Such an arrangement would have a free recoil velocity (25.2 fps) exceeding the recoil velocity (23.7 fps) of the .454 Casull (300 grs @ 1,650 fps) from a Super Redhawk.

Ouch. No thanks.