9x19 in 7,63x25 chamber

[Steinar]

Originally Posted by unspellable

The Winchester Tokarev stuff is relabeled ammo from a European manufacturer. S&B if I remember correctly. Which says nothing one way or the other for how hot a load it is.

That's scary news for me. S&B (Seller & Bellot) is a Czechoslovakian company, I guess you beleve they produce them by lisence?
Czechoslovakia have been using some very hot 7.62 ammunition in their CZ-52 pistol amoung others. It will not help reduzing my muzzle shake thinking it might be Czechoslovakian stuff i'm running trough my 70+ year old pistols

[Vlim]

Just wear eye-protection that's strong enough to catch the bolt

[Steinar]

Yes, I'm in no habit coming back home with a black eye. Will start using shades like the ones on Gerbens avatar

[unspellable]

Keep in mind it is labeled 7.62 Tokarev, not 7.63 Mauser.

[Steinar]

I checked the box, and you are abselutely right that it's made in Czechoslovakia. Find that scary..
So I tried it them trough a chronograph and got 1377 f.p.s, one original 7.63 Mauser round came out at 1368 f.p.s. A bit highter than the original ammunition.. but really not that much.
I would think ammunition made for guns like the CZ-52 would have a higher speed compared to the original round.. Please share your thoughts about this, could they be dangerous?

*Edit measued at 25m

[alvin]

Numerous Mausers have this "feature".... one picture from a Rock Island Auction session of 2007, please note the area behind the bolt stop.

Or worse, the 2nd picture came from an AuctionArm.com item.

[Steinar]

Wish I knew about this 'feature' before I purchased my Royal
The C96 I have sent most of the 7.62 Tokarev's trough is still ok.

[unspellable]

Stress on the bolt retainer and rear of the receiver is determined by bolt velocity, which in turn is determined by impulse, not pressure in an otherwise sound C96. The chrono velocity listed above is in the ballpark so I don't think it's a problem. The C96 is basically a strong design so pressure running a tad spiffy won't really hurt.

The real problem with catastrophic failure in a C96 is the hazards that come with old age. Bolt retainers and the retainer hole in the receiver have been known to crack as shown above. The locking lugs will become rounded with mileage, allowing unlocking to occur a bit early which will tend to raise bolt velocity. There is a fix for the last problem.

[alvin]

Thanks for the input, but I would reserve a little on the "worn parts" theory. It's hard to explain why some Mausers that lost almost all rifling still have straight edges behind the bolt stop, and some guns with excellent bore and much lower mileage have bent/deformed edges. I feel that the latter was still more related with firing higher pressure ammo.

Have not gotten a chance to inspect a damaged gun for detail yet. Will find one.

If the edge behind the bolt stop is very bent (like the 2nd pix above), the bolt cannot close completely. I just did a little experiment. By inserting a tiny cleaning patch between the bolt and the receiver, I created a gap of around 1m/m between them. Then, pushed down the trigger, the hammer did not fall.... the trigger had been disconnected from the sear. So, the gun shown in the 2nd pix is not functional anymore.

[Steinar]

Tried Alvin's experiment with the cleaning patch on the Royal I mention above. On semi auto it can't tolerate any more than just 1mm, but on automatic the hammer will release no matter how far back the bolt is. This gun is quite different internally than a C96 or M712, but I wonder if the same goes for a M712?

As seen on the picture, the top one has a small bulge on the upper part. Showed this one to Alwin earlier, he mention that it might be a softer metal than used in this one compared to the C96/M712.. makes sense to me, as it looks quite unused otherwise.

Is there any way to fix this? Or would that just make the metal more fragile in that area?

[alvin]

On Westinger Schnellfeuer (I have not gotten a chance to look at Nickl), the firing control switch does two things: it controls the width of the trigger and the position of the 2nd sear (full-auto sear).

In full auto mode, the width of trigger top is extended to raise the disconnector all the time as long as the trigger is kept pushing down, regardless the bolt position, so the 1st sear (semi-auto sear) does not lock the hammer anymore while the trigger is kept pushing down.

Also in full auto mode, the 2nd sear bar is enabled. The lower tip of the 2nd sear locks the hammer, and it releases the hammer when barrel extension touches its upper tip, just before the barrel extension fully returns to its forward position.

So, on Schnell full-auto mode, the hammer won't fall while the bolt is open wide even if the trigger is kept pushing down, because the hammer is locked by the 2nd sear. But the hammer will be released when the bolt and barrel extension almost returns to battery.

May I assume Royal has only one sear? If that's true, its full-auto mode was implemented more like "slam-fire".....

[Steinar]

Originally Posted by alvin

May I assume Royal has only one sear? If that's true, its full-auto mode was implemented more like "slam-fire".....

The mechanical design is packed down into the frame, it's a hassle to dissemble it.. So I'm not really sure if it has one or two sears. But the hammer does not release until the bolt is completely back into the forward position. First time hammer will fall by trigger pull, is not related to the bolts position on this broom look alike

[tomaustin]

possibly screw-up your pistol with improper ammo or loads??
the market is not in that bad of shape.

[alvin]

Originally Posted by Morgan Kane

But the hammer does not release until the bolt is completely back into the forward position. First time hammer will fall by trigger pull, is not related to the bolts position on this broom look alike

It's supposed to be two-sear design then. The behavior matches Schnellfeuer perfectly. When the hammer is cocked by finger, it is locked by the 1st sear. Pull out the bolt, the trigger is not disconnected from the trigger in the full-auto mode (vs in semi-auto mode, the trigger is disconnected), so push the trigger will release the hammer, even if the bolt is open.

Please note, the hammer is locked by the 1st sear in the first time cocking. Why the 2nd sear does not get involved in this step? It's because the barrel extension is in full forward position, so the 2nd sear is in 'release' position. Keeping trigger pushed down, the 1st sear is effectively disabled, the 2nd sear controls the releasing of the hammer in the following firing, until the trigger is released to re-enable the 1st sear, or the gun runs out of the ammo, bolt is hold open wide by the magazine follower.

Regarding "fixing" the minor dimple on the barrel extension.... It's not broken, better leave it alone. "No change in my hands". Just IMO.

[unspellable]

Bore wear versus locking bolt wear: The C96 started its career in the days of corrosive ammo, so bore wear doesn't correlate to mileage. Put the horse away wet a few times and the bore is shot even with low mileage. On the other hand, regardless of actual mileage, the locking lugs will progressively round off with additional mileage, whether the effect is slow or fast and no matter what the primer is. Hot loads might accelerate the process a bit, but the bottom line is still mileage.

There are after market bolt stops available. Some will recommend the use of a quality after market bolt stop in any C96 that is actually fired. I am not prepared to say they are wrong.

Be it a C93, C96, or C98, (I once got chewed out for calling a Luger a C98) they are all classy old gals that should be treated with respect and I don't recommend any load hotter than enough to reliably cycle the action for any of them. In the case of the 7.65 mm Luger, this may mean a hand load hotter than modern factory loads, at least those commonly available hear in the U.S.

[Steinar]

Originally Posted by unspellable

On the other hand, regardless of actual mileage, the locking lugs will progressively round off with additional mileage

Thanks for your input, I totally agree that these old guns should be kept away from hot loads.
What do you mean by round off locking lugs? I guess it's the area of the lug that meets the rear part of the upper?

[unspellable]

One side of the locking lugs are on the underside of the bolt. The other side is on top of the oddly shaped little locking piece under the bolt which is cammed down by the big oddly shaped piece when the cannon recoils. If you take the cannon (Upper on a browning action pistol.) off, it will not lock by itself, unlike the Luger cannon which does lock with out the rest of the pistol. This is one of those cases where a picture is worth a lot of words.

[alvin]

Actually, it's easy to see how bolt lock works even without a cut-away.

Unload the gun, open the hammer, remove the firing pin and bolt stop. Then, hold the grip and push the muzzle against a solid surface so barrel moves back to its rear most position, use the other hand to pull the bolt out.

Look into the square hole from the back of the gun, push the muzzle against the plam and release it, you will see bolt lock "teeth" swings down and up. The two locking cuts under the bolt match the position of the locking teeth on the bolt lock when the bolt is in the closed position.

=====

If I had said "Canadian Cannon" (Inglis), it would have been my invention. "Luger Cannon" was your invention. Not every pistol was entitled "Cannon" in old Oriental world Formally accepted nicknames were "Canadian Lu-zi", "Humpback Lu-zi". "Lu-zi" rougly means automatic pistol in Northern Chinese slang. General public did not study ballistics at that time, direct feeling was bigger pistols were more powerful than smaller ones, so entitled "cannon".

[Ron Wood]

And what about Pachelbel's Cannon?

[alvin]

Thanks Ron! I forgot this one.