.45ACP variant question

[hpcc19]

Can anyone shed any light on this issue.

I have always liked the Ruger MkI/II pistol action for .22lr. It was somewhat copied from the Nambu/Model 14 Japanese sidearm which I think was 8mm.

My question is: has anyone ever developed, or tried to develop a .45acp using this type of action?

I thought maybe the Avenger http://www.m1911.org/hogueavenger.htm was an attempt, but it seems quite different.

Thanks in advance for any insight.
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[Delmar]

The only one I can think of right now that even remotely resembles what you are talking about would be the Lugers chambered in 45 ACP. They only made a couple of them, and expensive is the understatement of the year if they would sell them to you. IIRC, somebody was making a modern stainless model in 45, but I cannot remember who it is/was. The Luger toggle link is very different than the Nambu action, but I think stronger

 

[hpcc19]

,45 Luger re: .45 Ruger

Thanks for responding. That was Mike Krause. http://www.krausewerk.com/ I don't know if he still makes them. They were ~10k-12k. I guess the recoil/bolt action is similar with a different spring mechanism.

 

[Jim K]

Oh, boy, fruit salad.

The Japanese Nambu is a recoil operated, locked breech pistol using a rear locking block that pivots downward to unlock the bolt from the barrel extension after the bolt and barrel have stayed locked together until the pressure drops.

The German Luger is a recoil operated, locked breech pistol using a toggle mechanism to lock the breech block and barrel extension together until pressure drops. It has almost nothing in common with the Nambu except a very vague general appearance.

The Ruger .22 is a pure fixed barrel blowback, locked only by the mass of the bolt. It is in no way a copy of the Nambu, and its resemblance to the Luger, while deliberate, is totally superficial; the pistols operate entirely differently.

To build a breech lock into the Ruger system and make it in .45 might be possible, but with other more practical systems on the market, it would have no real reason other than just to see if it could be done. The gun would, of course, have to be much larger, which would take away the neatness of the Ruger design. I recommend not holding one's breath waiting for it.

Jim

 

[hpcc19]

Ruger again

Thanks for the technical explanation(s).

"The Ruger .22 is a pure fixed barrel blowback, locked only by the mass of the bolt. It is in no way a copy of the Nambu, and its resemblance to the Luger, while deliberate, is totally superficial; the pistols operate entirely differently."

This seems like the same mechanism of my 1927 semi-auto Thompson, fixed barrel, straight blowback, locked by the mass of the bolt. (which weighs about 2 pounds)

Am I on the right track? I was originally just wondering why no one had seemingly followed this path of development.

 

[SDC]

The problem with using blowback in a handgun is that you quickly run up against a point where the slide/bolt/etc. ends up being so heavy that it's impractical and unwieldy for a handgun (which, in theory, at least) is supposed to be a light, easily-transportable item. The only currently-manufactured blowbacks that I'm aware of that are chambered in a calibre above 9mm are the Iberia/Hi-Point .40s, and on those, the slide is so heavy that you get almost a "double recoil" sensation, first from the projectile being fired, and then from that heavy boat-anchor of a slide slamming back and forth. There were a few straight blowbacks tried early on in 45 calibre (the Schouboue pistol being one), but to get it to work they had to reduce the weight of the bullet by using a wooden-cored bullet.

 

[Jim Watson]

I think the Sokolovsky .45 is blowback or retarded blowback operated.
He made 50 of them for $5000 each about 20 years ago.

 

[Jim K]

Hi, hpcc19,

Yep, the Thompson semi-autos are blowback. Not only are the bolts heavy but they also have such a humongous recoil spring that it takes two men and three small boys to cock the gun.

The Thompson SMG has no such problem; it (like all open bolt SMGs) uses something called advance primer ignition to fire the round just an instant before the bolt fully closes. That means back pressure has to fight not only the static mass of the bolt but the residual forward momentum as well. In other words, API allows the bolt to work as if were much heavier than it is.

With closed bolt firing (required by BATFE) API cannot be used, so the bolt mass has to be higher, and the spring heavier to slow the bolt down.

Jim

 

[ABTOMAT]

The older Thompsons also had the Blish (love that name) delay lock. I guess the heavier bolt did away with the need for that.

 

[hpcc19]

One more for Dr. Keenan

What was the operational method of the M1907 Savage trial pistol

http://i25.photobucket.com/albums/c54/hpcc19/1907Savage.jpg

http://trans.voila.fr/ano?anolg=65544&anourl=http://www.hlebooks.com/savage/savage1.htm

 

[deadin]

What was the operational method of the M1907 Savage trial pistol

Rotating barrel. Barrel rotated about 3 degrees and then released the bolt.
A few other "rotaters" of note were the Steyr-Hahn, Roth-Steyr and the Obregon.

As for the "Blish" lock, it supposedly worked on the "inclined plane" and friction principle. Last I read was that the jury was still out on whether it did anything at all.

Dean

 

[Jim K]

Hi, Abtomat,

There has always been debate as to how much effect the Blish lock had, but the reason it was discontinued was to reduce complexity for volume production in WWII. I haven't weighed bolts, but I don't think the M1/M1A1 bolts were much different in weight from the combined bolt and actuator on the old guns. The Blish lock did have some effect, though, as the later guns had to be strengthened considerably at the back end compared to the older ones.

Hi, Deadin,

The Savage pistols were delayed blowback rather than having a true locked breech. The other guns you mention are actually recoil operated and the barrel and slide remain locked together while the barrel is turning to unlock. The Savages had no real lock; supposedly, the bullet impacting on the rifling tried to turn the barrel the "wrong way" thus delaying or retarding the blowback. I suspect that worked better in theory than it did in practice.

While the Searle system worked OK for the .32 and .380, it just plain was not strong enough for .45. The guns battered themselves to death in the trials, with broken parts all over the place. It is noteworthy that, once the Army trials were over, Savage never even attempted to field a .45 ACP (or even a .38 ACP) on the civilian market.

It is also interesting to examine the reason for the unique Savage system, as well as other unusual systems used by Remington (Pedersen design), Smith & Wesson (Clement design), Davis Warner, and others. Mostly the designers knew full well that their systems were more complex than necessary, with what seem today to be odd features. The reason was that one fellow, named Browning, had patented everything he could think of that might help competitors. One of those patents covered a slide with an integral breechblock, hence those designs used separate breechblocks. Browning even patented the idea of holding grips on with screws, forcing the others to use other, less satisfactory methods.

(Edited to add: Deadin, we both forgot the (in)famous Colt AA2000, the "gun of the future", which is a rotating barrel locked breech. I felt it should be mentioned, but now we can both (thank heaven) go back to forgetting it again.)

Jim

 

[deadin]

Jim,
You're right. Savage tried to call it a "locked" breach. (and didn't get away with it. )
Speaking of "complex" systems. Have you ever checked out the Frommer Stop? It qualifies as a long recoil system where the barrel and bolt/slide stay locked for at least the length of the case before unlocking.
The cycle was 1. Barrel and bolt locked together at time of firing. 2. Both parts recoil (while locked) to the full extent of their travel. 3. Then the bolt unlocked allowing the barrel to return to battery, stripping it off of the empty case. (the barrel had its own spring). I believe there was an "ejector" that kicked the case out. 4. After the barrel had returned forward, the bolt was released and picked up a fresh round from the magazine, chambered it and locked for the next shot.
The barrel spring and bolt spring shared a guide rod and had an adjusting nut between them so you could "balance" the tensions to try to make everything work properly.
All this for a pistol designed for .32 ACP!! Talk about over-engineering.

Dean

 

[Lo.Com.Denom]

And you both forgot the Colt OHWS, Beretta Cougar series, the MAB Model R, MAB PA 8 and PA 15. Isn't the new Beretta PX4 another? I'm sure we're forgetting some others...

What were we talking about again...?

 

[hpcc19]

Please bear with me--if you have time and patience

A .22lr has about 130 fp of energy leaving the muzzle. A .45 has about 370 fp.

This should somehow be proportional to the energy that the slide mass, recoil spring and mainspring have to absorb when cycling these handguns. Yes/No?

The Ruger has a mainspring, recoil spring, a moving bolt mass, and no bolt/breech lock.

The 1911 has a 16# recoil spring, a 23# mainspring, a 13 oz. slide mass and no breech lock.

It would seem to me that if these resistance factors were kept relatively consistent on a Ruger type pistol, then it should be operational for .45ACP. I figure the bolt would need to be about 1" diameter. The trigger, sear, hammer and firing pin configuration seems adaptable to a centerfire design.

I know, as someone already said, what's the point of the exercise. Maybe I'm just looking for a fun retirement project.

I have 2 hours of firearm design experience stacked up against about 115 years of semi-auto pistol design heritage by thousands of people, but what the hey? That's why I'm consulting the experts.

 

[SDC]

But the 1911 DOES have a "breech lock"; the slide is locked to the barrel for the first few (hundreds?) of a second after firing, during which both the slide and barrel together recoil to the rear. After that travel, the link pulls the rear of the barrel down to unlock it from the slide, but by that time, the bullet has already exited the barrel and the internal pressure has dropped to ambient. From that point on, the slide is only working on its retained inertia, compressing the recoil spring as it extracts and ejects the fired case, then being driven forward again to pick up a fresh round from the mag. I have no doubt that you could make a .45 slide heavy enough so that it would FUNCTION as a straight blowback, but it would require either a slide so heavy that no-one would want to CARRY the pistol, or it would require some other engineering trick like annular grooves/rings in the chamber to delay opening until AFTER the internal pressures drop to a safe level (like the Kimball 30 Carbine pistol, which was right on the ragged edge of safety).