Broomhandle Mauser Barrel re-lining

[tark]

Will, perhaps JonnyC can weigh in on the question of whether or not the Czech's loaded super hot ammo for the CZ52. I think he has probably forgotten more about 7.62X25 ammo than the rest of us will ever know. I have fired a lot of Czech surplus in my Tokarevs and also in my Broomhandle. I honestly cant tell any difference between it and anybody else's surplus.

A lot of people don't seem to realize that a broomhandle is an enormously strong pistol. It was chambered in a round, the 9X25 Mauser, that made a 38 Super look positively sissy by comparison. A 128 grain bullet at 1360 FPS is not exactly a weak round!

I have always heard that Czech CZ52 ammo is loaded a couple of hundred FPS faster than standard Tokarev ammo, but that doesn't necessarily mean it is loaded to higher pressure They are loading white box ammo for Winchester, today, and that ammo gets about 250 FPS more than the original 7.62X25 load. But it is loaded to 35,000 PSI which is pretty much standard pressure level for 7.62X25.

Advances in powder technology will work wonders.

We need ya' JonnyC! Straighten us out on this one

 

[Dave Markowitz]

From the FWIW department:

Last month I took out my Broomhandle, which has a very worn bore. Before shooting it I replaced the hammer and recoil springs with new springs from Wolff. I fired two kinds of ammo through it:

1. Hansen .30 Mauser, made by Prvi Partizan.
2. Yugo military surplus 7.62 Tokarev, also made by Prvi Partizan.

The pistol would not cycle when fed the .30 Mauser ammo. It would fire, extract the empty case, but fail to eject it. In contrast, the gun functioned perfectly with the 7.62 Tok, which produced more recoil and had noticeably more muzzle blast.

So, not all .30 Mauser is loaded to the same specs as 7.62 Tokarev ammo. Or, some 7.62 Tok ammo is loaded hotter than others. Without chronographing various types of ammo and also measuring the chamber pressure, IMO it's improper to make generalizations about the equivalence or lack thereof between .30 Mauser and 7.62 Tok. There have just been too many manufacturers of .30 Mauser and 7.62 Tok over the past century.

Note, too, that this says nothing about the strength of the C-96.

Bullets from both loads keyholed at 10 yards, so I'm sending the barrel off to Redman's for relining.

 

[barnbwt]

Whaddya suppose the odds are the folks at PRVI have the same rumors about wimpy C96 Mausers blowin' around?

TCB

 

[Dave Markowitz]

It would not surprise me in the least if they download .30 Mauser ammo for the American market, out of fears of litigation.

 

[Carl N. Brown]

On Topic: relining a C96 or alternate solution?

I have one of the "sewer pipe" barreled surplus C96 pistols (in otherwise sound mechanical condition) and did consider relining the barrel at one time or the other. Fully cleaned of copper fouling, the barrel looked like polygonal rifling, very very eroded, barely there, but shiny lands and dark grooves.

It shot poorly at 25 yards with SBP 7,63 Mauser ammo and often keyholed with S&B 7.62x25 ammo (SBP Sellier&Bellot prewar, S&B Sellier&Bellot postwar). I did well to keep all shots in the scoring area of the 25 yard pistol target shooting from sandbags from the bench (target 5 ring ~20", 10 ring ~3.5").

I pulled a bullet from a 7.62x25mm round and pushed it through the barrel with a cleaning rod. It barely touched what was left of the eroded lands of the rifling. The bullet was very close to .308" diameter.

But I started shooting my C96 anyway. For the local blackpowder matches as a single shot. S&B reloadable cases, 1.0cc Pyrodex P, overpowder card, borebutter, 00 buckshot (.32"). Shot pretty good.

I got to thinking. In the mountains, when your muzzleloading rifle became worn but still had rifling, you would take it a blacksmith and have the barrel "freshened": the grooves cut a bit deeper, the lands polished, and your bullet mold re-cherried to the larger diameter.

I figured, that might work with my C96.I pushed a buckshot through the bore and determined that the groove to groove diameter was .312" same as ".32" caliber pistol. Since then .312" 85gr JHP revolver bullets and .312" 72gr FMJ auto pistol bullets have given me good accuracy. I shot a 25-yard target with a score of 95-2x off hand.

Going to reloads with a bullet that fit worked for me. Your mileage may vary. And yes I do still think about having the barrel relined, but it is hard to justify the need.

Off topic: 7,63 Mauser v 7.62x25mmTT

When I got my used C96 I bought a Wolffspring set and noted both the old hammerspring and bolt spring with the gun (ser. num. range 107xxx = ~1912 manufacture, pre WWI) were weaker than the new springs. With the C96 design, the hammer spring slows the recoil of the bolt more than the bolt spring, which in my not so humble opinion should be called the bolt return spring: the hammer spring is the recoil spring. You can have a C96 hammer spring that will fire a cartridge fine but allows the bolt to recoil 'til it impacts the bolt stop. The C96 bold stop does not crack. The C96 barrel extension (upper receiver) first peens, then starts bowing out, then cracks behind the bolt stop. First you will see peening of the barrel extension behind the bolt stop. It is telling you "I need a new hammer and bolt spring". If the back of the bolt extension is bowed out behind the bolt stop, it is too late. You have a wall hanger. I don't want to see the barrel extension fail and the bolt fly out the rear of my C96.

It is not pressure, but recoil impulse that damages the bolt stop. I suspect what people call the subgun load, the Czech M48 introduced for their submachineguns, uses a slower and longer burning powder, not higher pressure, to get higher velocity and greater recoil impulse. The slide and recoil spring on the Czech CZvz52 pistol handle heavier recoil better than the Mauser system. The CZvz52 pistol barrel is not stronger than the Mauser barrel, but both barrels are adequate for their specified ammos. But if you go Mad Maximum Overload, the Mauser action will fail when the barrel will stay intact while the CZvz52 action will stay together while the barrel will fail.

As far the ammo spex, these are what I have found published:

7.62x25mm Tokarev, various sources.

Prvi Partizan PPU Serbia factory spex
7.62x25 85gr bullet 525 mps (1706 fps) from 250mm 10 inch barrel.

Sellier&Bellot S&B Czech factory spex
7.62x25 85gr bullet 503 mps (1630 fps) from 120mm 4.8 inch barrel.

W.H.B. Smith, "Small Arms of the World", Stackpole, 1966
7.62x25 Russian WWII issue, 1640 fps from 10.6 inch barrel (PPSh 41).
7.62x25 Russian WWII issue, 1378 fps from TT33 Tokarev pistol.
7.62x25 Czech M48 ammo, 1800 fps from 11.2 inch barrel (M24 and M26 SMGs)
7.62x25 Czech M48 ammo, 1600 fps from CZ52 pistol.

.30 Mauser, 7,63 Mauser, 7.63x25mm Mauser

W.H.B. Smith, "Small Arms of the World", Stackpole, 1966
7.63 Mauser WWII issue, 1575 fps from 5.5 inch barrel, Mauser 1932 M712 version C96

Prvi Partizan PPU Serbia
7.63x25 85gr bullet 460 mps (1495 fps) from 150mm 6 inch barrel.

U.S. commercial .30 Mauser in the 1970 Gun Digest
7.63 Mauser US commercial, 1410 fps from C96 .

Fiocchi commercial
7.63 Mauser 88 gr bullet, 1425 fps

opinion

Again my not so humble opinion is that commercial loads in .30 Mauser and 9mm Luger have been deliberately downloaded to be used safely in war trophy souvenir guns of doubtful maintenance or repair. The German WWII ammo was issued for new manufacture pistols, not for antiques.

The German WWII 7,63 Mauser ammo loaded for new issue Mauser M1932/M712 pistols was also issued for use in PPSh41 submachineguns captured by the Germans and the Finns and worked quite well. By what I have read, WWII German 7,62 Mauser and WWII Soviet 7.62 Tokarev were pretty equivalent.

Frankly though, Eastern Bloc 7.62x25mm pistol ammo is all over the spectrum of velocities and pressures.

 

[Dave Markowitz]

Lots of good info there, Carl, thanks. Using larger diameter bullets to get accuracy makes sense in a worn bore. However, while I may eventually get around to reloading 7.63 Mauser, I want to be able to shoot factory loads in it. So, I have my C-96's barrel and bolt all boxed up and ready to go out to Redman's tomorrow.

 

[SHIPCHIEF]

I bought a 1930s Broomhandle about 25 years ago, (Pacific Merchandising International?) it was shot out. I shot it twice, the cases were belled out!
I saw an ad in the gun news, Labounty Precision Re-boring in Blaine WA.
I gave him a call and he was very helpful. Being young, and wanting to up the ante while refreshing a cool old non-collectable piece, I elected 38 Super.
Cliff cuts off the barrel, bores & threads the slide. He starts with an 8" long barrel blank, which he threads to match. He threaded the barrel to the slide and silver soldered them together. He will cut the barrel to your requested length and silver solders on a front sight. I selected the full 8" barrel, no sight.
I was going to install one of those new fangled Red Dot sights. Somehow that project languished, but I have loaded and fired it with 38 super +P ammo, 130 gr FMJ, American Eagle brand. Works good. Pretty impressive! The whole gun twists in reaction to spinning the bullet down the barrel. (the thrust line of the barrel is fairly high above the grip)
Pistols with the magazine ahead of the trigger are not so uncommon now with AR & AK pistols on the market.