M92 cartridge experimentation

[jamesgpobog]

This is a post combined from several I've made at Rossi Rifleman concerning some (I think) outside-the-box ideas about using the M92 .357 as an urban self defense trunk gun.

First, concerning wadcutters...

While playing around with COAL with full wadcutters seated out (dummy rounds, no primer or powder), it seems I might have stumbled on a 'sweet spot', because I have dummies in both .38 and .357, BBWC (SNS Casting) and a H&G button nose (Bayou) that feed slicker than snot.

The SNS WC is .574 long, the Bayou is about .576, however, the distance to the shoulder on the Bayou is .068 in back of the nose. That means for a given OAL, the shoulder of the H&G design is going to be about .065-.068 closer to the case mouth.

SNS Casting poly coated boolit (gold).
.358
148 grain BBWC
8 grains Unique (old)
Taper crimp, just below crimp groove. Groove fully exposed.
OAL 1.406

Bayou Bullets poly coated boolit (green).
.358
138 grain (per website) H&G style Button Nose BBWC
15 grains Hercules 2400
Roll crimped in 2nd groove from nose (first lube groove)
OAL 1.475

Then I started thinking about increasing magazine capacity...

My 16" M92 holds 9 .38spl's FMJ flat nose (@ 1.43" OAL) in the tube.

I'm looking at .38 S&W brass, sized through a .357/.38 die, loaded with 125gr RNFP coated boolits, with 4+ grains of Unique (up to 4.5?) at about 945fps (pistol barrel). Add 200 fps for the rifle tube, and it's getting close to 1200fps and kinetic energy in the zone of at least a 9mm.

What's the payoff? The math says that I should be able to get 13-14 of them in the magazine. For an urban self defense gun, I think that is significant...

The biggest unknown right now is how COAL length works out feeding...

And finally, load development...

Is this a correct way to develop loads? Obviously, I do not want to blow myself up, and also obviously I'd like more performance in the cartridge than normal .38 S&W (NOT .38spl) loads.

Existing load data is always safe for old top breaks, so the range I'm looking for is extremely rare.

I have looked at case dimensions, and the 9mm is very close to the 38S&W, though the 38 is slightly longer, the 9mm is very slightly fatter. I think for my purposes the volume differential is nominal.

So, since the S&W will be sized to .38spl dies, am I correct in thinking that I could look at 9mm cast boolit data, reduce 10% and work up? I'm looking to use coated 125gr RNFP.

So, that's what the fertile imagination has produced so far. I'm not a complete noob, but am far from an expert. Any thoughts/help will be appreciated.

[AJMD429]

Feeding issues probably CAN be solved, because plenty of guys do fancy short-cartridge modifications of leverguns. It may take some time and patience.

You will be chronically feeding shorter-than-chamber-cut cases, so may develop the proverbial 'crud-ring' in front of the case, which can be problematic if you try to shoot regular cases later.

The pressure issue is probably going to be the most vague to deal with, and of course could go really 'bad' if you mess up.

Still, the real issue boils down to exactly what you said - the amount and type of powder, the volume of the case, and the bullet diameter and weight. Mostly the mistake people make is doing stuff like taking 357 Mag data, loading it into a 38 Spl case, and assuming that it will be ok in the same gun that could take the 357 Mag pressures; what they've done is create a potentially much higher pressure round, due to the same amount of powder in a smaller space. Or they neck down something and assume the pressure won't change; it will.

Fortunately, the Rossi is a strong design, plus there is even more metal thickness with the 357 caliber vs. the larger bores (though that doesn't necessarily help as much as people assume).

I think leverguns are great low-profile urban-defense weapons. The ONLY issue boils down to the [stupid] legal one that most of the time [although you can carry a loaded concealed handgun on your person] you are prohibited from having a loaded magazine in a rifle in your vehicle (or in some instances in your home ).

Here's a few of my 'Night Scout' home-protection leverguns...

> Night Scout leverguns

[BigSky56]

I dont follow on the idea of using reduced loads in a truck rifle for SD yes for a mercy shot on a injured animal on the road if you dont have a 22. gunfights are tough enough with a standard rifle with spec ammo using a reduced case, powder or bullet can cost you some hide. danny

[JerryB]

Kinda thinking the same thing about lower powered loads for self defense.

[Old Ironsights]

#1.... Why on earth would you think that using a .357 Levergun is "outside the box" for a bad times/Truck gun????

#2... Why mess with a good thing? OEM ammo (.38 or .357) is 110% effective for bad times/Truck gun use.
I load OEM 180gr SJHP Federal Premium as my "carry" load. Yes, I use either handloads or Buffalo Bore for HUNTING, but for EDC, the Federal 180 SJHP is a hard one to beat.

The REASON to have a .357 M92 is that it is effective with EVERYTHING (OEM) stuffed into the chamber.

Be happy and let it do it's thing... and match the Rifle ammo to your sidearm. Supply trains are a PITA...

[Nate Kiowa Jones]

You might want to check out this topic.

Rossi 92 overall cartridge lengths?

[Malamute]

I'd suggest that two factors would overule any potential advantage of a couple extra rounds in the gun. First is that jacketed hollow points will be far more effective than a cast wadcutter on nearly anything you'd want to shoot, making the need for the extra rounds less of an issue. The other is the question of using different loads in the carbine than your pistol. Using the shorter rounds will make the crud/carbon ring in the chamber, which can cause problems if you then use longer cases at full power. Using the short cased rounds in a pistol will not allow as powerful of loads to be used as when using the regular magnum cases. 38 spl gets very close, but theres still somewhat of a pressure penalty if wanting to run them at full power.

I'm thinking making the first rounds in the gun more potent (staying with full power magnum JHP loads) is a better plan than using less potent rounds and having an extra round or two.

[Griff]

There's an old adage... if you want more power, get more gun. This could be applied to both how powerful the cartridge is... and how many rounds you have. All your options have trade-offs. A longer barrel to gain more magazine length to gain more cartridges increases overall length. Another style arm will almost always increase the length of the arm... most semi-autos have a longer action, even with the same length barrel... but... with a detachable magazine, you can significantly increase the number of rounds.

Myself... I don't worry about it, I carry a mdl 94 Winchester Trapper in .30-30; it hold five rounds. Light, handy and eminently powerful enough for what I'd anticipate encountering. Add a butt cuff with an additional 10 rounds... The nice thing about either the mdl 92 or mdl 94 actions, they are about the shortest that you can have in the power category you select, be it .357Mag, .38Spl., 44 Mag, 45 Colt, or .30-30!

You ain't gonna make a silk purse out of a sow's ear... but there ain't a thing wrong with a pigskin one!

[AJMD429]

There's an old adage... if you want more power, get more gun.

Good point.

One option would be to get one of the other-chambered Rossi leverguns; same barrel length equals same number of magazine rounds in 357 Mag, 44 Mag, and 45 Colt. 454 Casull may lose one, but I'm not sure.

Those little 16" Rossi 92's in ANY chambering are handy and would be grand self-defense guns. The bigger-hole ones might make a person feel less handicapped with only 8 rounds, but - realistically, if you needed 9 rounds, you should have stayed home, or brought your AR-15 or M1A.