Design the ideal mousegun/caliber?

[the naked prophet]

The recent mousegun thread got me thinking. Most of the mousegun calibers are very old - .32 auto, .380 auto, .25 auto, .22LR and so on. They are all low pressure rounds, even the new .32 NAA is a low pressure round, limited by the pressure of the .380 since it uses that brass.

What would be the ideal round for a mousegun? Using modern materials, designing a high pressure round for short barrels and thin guns.

Okay, I'm thinking that it needs to be at least as powerful as a .32 but better if closer to the .380 in power. A rimless case would help the feeding issues, and centerfire is much more reliable than rimfire. The bottleneck doesn't do much for velocity in such a short barrel, so a straight case would probably be more efficient.

A straight-case rimless centerfire high pressure cartridge. The high pressure probably requires a locked breech, which will also reduce recoil for the shooter.

A double stack magazine would be an interesting feature in a mousegun - if you could get thin enough rounds for a double stack in a mousegun sized grip, you would probably have maybe 10-15 round capacity? Interesting idea anyway.

I'm thinking something along the lines of a straight walled case with a .30 caliber heeled bullet (larger bullet diameter without the added thickness of the case taking up space in the magazine). Something similar to a 5.7x28mm case cut down, maybe a tad smaller to fit a heeled .30 cal bullet. With the near-rifle pressures, and a very fast burning propellant (with a polygonal rifled bore) you could get some decent velocities out of a mousegun length barrel.

15 rounds of hot .30 cal in your hand, not bad. I'd take that over 7 rounds of .32 auto, or even over 6 rounds of .380 auto.

Think you can get decent ballistics from something like that?

 

[Plink]

In my opinion, the perfect mousegun caliber is already out there. The 9mm. It's powerful enough to be pretty effective, works good in short barrels, has moderate recoil for it's power and isn't much bigger than the .380. There are some mighty small guns made for it too. It kicks pretty hard in small guns, but any time you increase "power", you increase recoil anyway, regardless of bullet diameter.

I guess we could try to increase velocity by going with a smaller bullet, but velocity and energy in and of themselves, don't do anything. Tissue damage is what matters, and a small bullet going fast really doesn't have any benefit over a larger one going slower.

 

[usmccpl]

Why would somebody want to use such a light powered weapon for self d. The Kel-Tec 9mm aint very big. And if you can find one an AMT back up in 9mm 40 or 45acp aint any bigger than the 380 models and not much bigger than most others.






one shot one kill

 

[kokapelli]

-
Rohrbaugh!

 

[HorseSoldier]

A compact pistol in FN's 5.7mm round would probably be interesting. Not sure if I'd want to bet my life on its terminal performance, but you'd probably still have something like 16+1 in the gun, so repetition would be possible if one round did not do the job.

 

[Plink]

The 5.7 makes a lot of sense in its original carbine design. Short, light, high cyclic rate with low recoil, enough ammo to be able to fire large bursts to ensure quick stops. But in a short handgun barrel where you aren't going to be firing bursts, it just comes up lacking in every way I can think of. Just my feeling on that one. I wouldn't use it for self defense in a full sized handgun, much less a pocket sized one.

 

[the naked prophet]

I don't like the 5.7 round either. But if you cut down the case (or blew out the neck) to make it a .30 caliber, I think it would do a lot better in terms of terminal ballistics (though it probably wouldn't penetrate armor at all). Maybe even on par with .32 H&R Magnum.

Keep in mind, many people find the recoil from the Rohrbaugh to be too much, and the magazine capacity to be too small. Personally, I'd rather have 15 rounds of something in the power range of .32 H&R Magnum than 6 rounds of 9mm in a tiny pocket gun.

 

[Jim Watson]

Mechanically feasible, si.
Worth doing? I dunno.
By the time you make a double column magazine and a locked breech for a .30 Pistol, you have a gun as large as a compact 9mm P.

Settle for a single column magazine, maybe a delayed blowback action of the very best materials, and you could have something the size of a .32 but more powerful.

But that is what NAA has tried to do with their little bottleneck and it does not seem to be flying off the shelves.

 

[Sistema1927]

I think that Justin Moon has come pretty close with the Kahr PM9.

 

[the naked prophet]

I see the PM9, and I see the bottlenecked cartridges. Neither use a modern round designed for a tiny gun. The 9mm is old, as is the .32 and .380 and the NAA bottlenecks are limited by the old-style low pressures of the parent cases. The NAA bottlenecks are very inefficient because of the short barrel.

The 9mm was designed for a military sidearm - full length barrels and submachine guns. What I want to do is design a round specifically for a mousegun. I think you can get a double stack mag thin enough for a pocket gun. I think in a gun the size of the Kel-Tec P3AT, maybe using the magazine sides as the grip panels, you can fit a double stack magazine. The .30 cartridge would make the barrel thinner, and I think the slide wouldn't need to be any thicker than the KT P32 slide. Hmmm.

I think I'm gonna order some 5.7x28mm brass, some .308 pistol bullets, and see about working up a load. Then I'll maybe try to get a barrel made for a PF9 and see how that works. This could be fun.

 

[kokapelli]

-
Seems to me the 7.62X25 round that has been around longer than me (and I'm old), would fit your requirements very nicely.

A 30cal, 85gr bullet at around 1500fps out of a four inch barrel!
What more could you ask for?

 

[David N]

The gun has already been designed. It is very accurate due to its fixed barrell. It offers reliable "blowback" operation with few parts. It is safe, has a light SA trigger pull, and is so easy to strip and clean that even I can do it. It's called a Makarov. If only they were available in 9mm Luger I wouldn't own anything else.

 

[Chipperman]

9mm is too hot for straight blowback.

 

[dust_101]

Keep in mind the 32NAA is not being produced by Winchester or Remington, CCI, etc which is keeping alot of folks (myself included) from buying one. It is a good round overall, I mean if you shoot someone with the 32NAA or a 9mm and actually hit them it'll work =)

Shot Placement = Good

How about changing the 5mm Craig for a pistol... er no nevermind

 

[kokapelli]

I have to agree with Chipperman.
I have two Makarovs and even with the much weaker 9X18 round, the Mak really hammers my hand without having the thick rubber, Pierce grip installed.

 

[Brass Fetcher]

Colt Pocketlite with polymer frame and chambered in .32NAA. I haven't found any other mousegun caliber that works as well as this cartridge and the SA action, great ergonomics of the Colt Pocketlite make it suprisingly shootable, at least to me.

 

[Sylvan-Forge]

JE223,
Did I read you wrong or did you just say that you have chambered the Colt Pocketlite in .32 NAA?

Please, do tell!

 

[Brass Fetcher]

It would be an even better trick to make the frame in a polymer configuration! Seriously though, I haven't done a caliber conversion on this pistol - I would like to see something like that mass produced.

 

[Soybomb]

I think thats the 9mm. And I think the rohrbaugh r9 is pretty close to it with its locked breech design. It needs a genius engineer to bless it so that they're more reliable out of the box and far less ammo sensitive and perhaps tweak it to something more affordable.

Its a shame keltec didn't do one instead of just turning their bigger 9mm into a single stack and saying that solved the problem. Might have taken a while to run out the reliability part, but it would have been affordable.

 

[the naked prophet]

I understand that the Rohrbaugh 9mm is quite the little gem. I know a couple guys who carry them everywhere.

My problem is that the 9mm was not designed for a short barrel. It also was not designed to utilize the space in the most efficient way, both the space in the barrel and the space in the grip/magazine.

I think you can get a respectably powered load in a mousegun that will have less recoil than 9mm (from such a tiny gun) and twice the capacity. The smaller case will allow a thinner barrel and slide.

I dunno. Maybe I'm obsessed with efficiency. The Rohrbaugh is a great adaptation of the 9mm to the mousegun category... but it's still an adaptation.

 

[Soybomb]

Designed for a short barrel or not, 9mm seems, at least to me, to do very well in short barrels.

http://www.hipowersandhandguns.com/9mm vs 38 Special.htm shows
wwb giving 1097 fps from a g26, and 1072fps from the rohrbaugh. With a 5" barrel you could knock that up to what, 1300fps? That doesn't seem terribly inefficient to me.

I understand about inefficiency every time I look at the case for a .38spl though

 

[HankB]

Well . . . the .357 Sig is a necked-down .40, so maybe for a mousegun we can take the 9mm and neck it down to .30 . . . higher velocity, lighter bullet, and we can give our new cartridge a nice catchy name, like ".30 Luger."

Seriously, a mousegun is a mousegun and until there's some major breakthrough in propellent technology, allowing GREATLY increased velocity out of a small package, trying to design an "ultimate mousegun" remains an exercise in making a silk purse out of a sow's ear.

 

[ABBOBERG]

+1 on "adaptation". What we need is a mouse gun with a full length barrel to capitalize on ammo designed for it. I have not seen any gun manufacturer make any attempt at re-engineering the pocket pistol to maximize barrel length, and hence, performance. All they do is chop the barrels and grips off their larger guns and call them "compacts", "sub-compacts" and "pocket-sized".

In 9mm, with a full length barrel (4.2"+), you can get 1220-1250 ft/sec out of ammo that only gets 1050-1100 ft/sec out of the 3" barrels. A lot of hollow points will not expand under 1200 ft/sec.

So, when it comes to "lost opportunities" in the mouse gun market, I put the burden of the blame on the gun manufacturers, not the ammo manufacturers since there is a lot of good ammo out there.

 

[the naked prophet]

Seriously, a mousegun is a mousegun and until there's some major breakthrough in propellent technology, allowing GREATLY increased velocity out of a small package, trying to design an "ultimate mousegun" remains an exercise in making a silk purse out of a sow's ear.

That is exactly my point. We have had major breakthroughs in propellant technology since the invention of the 9mm. With a case which can withstand very high pressures (such as the 5.7 case) you can use a very fast burning powder with a compressed charge, and shoot a heavy-for-caliber bullet at very high speeds for a short barrel. Combined with a double stack mag (cause the cases are so small) and a grip without side panels (the sides of the mag are the sides of the grip) I think you've got a true pocket-sized gun with high capacity that's got power in the .38 spl or even lower 9mm range.

We have made the breakthroughs, but they have only been applied to adapt ancient cartridges to short-barreled designs.

 

[vesmcd]

I would like to see something in the Kel-tek style chambered for the old French 32Long, pumped up to about 1000fps.