Rotating barrels?

The Savage automatics with only 5 degrees rotation and depending on the Searle Effect to torque it shut a little longer might fall into delayed blowback.
The MAB R9, unlike its successor the PA15, had a cam cut that let the slide start back immediately the barrel started rotating, also another delayed blowback suspect.
 
Interesting. I have not had the opportunity to examine those guns.

The PX4/Cougar, the Grand Power and, from what I can tell, the Glock in the article all use a locked breech system. The Glock system appears to be very similar to the PX4/Cougar system which uses a "tooth" on the barrel and a separate locking block with a "channel" that the tooth engages to perform the unlocking operation.

I wish Glock had gone with the Grand Power system as it is lighter, more compact, and doesn't require a separate locking block.
 
carguychris said:
I don't read German, but I strongly suspect that the contract requirements either require a rotating barrel outright, or effectively prohibit a tilting barrel.
Click to expand...

The Ulm Proof House publishes a list of guns certified as meeting the German "TR" police requirements; none of the certified guns have rotating barrels.

While a rotating barrel is not an explicit requirement, some combination of requirements must have led Glock to its solution involving a rotating barrel.
 
The best known example of a rotating barrel is in the common Steyr-Hahn (Steyr-Hammer) pistol. A rotating barrel is inherently more accurate than a tilting barrel design because it is more fully supported and its motion is straight back and forth with no tilting and fewer problems with barrel re-set when returning to battery. A down side is that the locking lugs make the barrel larger in diameter, something that is obvious in the PX4.

But the rotating barrel is definitely a locked breech, the same as a 1911, just a different way of achieving that. (Some say it is a delayed blowback since the barrel begins to rotate when the slide moves. True, but so do most "locked breech" pistols.

Jim
 
Delayed blowback is different from short-recoil... Short recoil always involves some form of locked breach, while delayed blowback doesn't (delayed blowback may have a locked breach but usually doesn't).

All rotating or tilt barrel pistols in common use are short recoil operated. I'm sure there may be an oddball out there somewhere, but it will not be in common use.
 
and not least because of the slow speed unlocking. A minimum unlocking stroke is to be noted.

Advantages of the new gun model. The first important advantage is the symmetrical, bore-axis arrangement of the opposing locking nipples. This is beneficial if you use higher-performance ammunition.
Click to expand...

Not saying I called it or anything, but...

I will propose one theory. I do believe that a rotating barrel can be designed to increase lock time beyond what would be possible with the tilt barrel system. This, theoretically, may allow you to up the durability of the firearm while shooting stout loads
Click to expand...

Hey give me my moment :D
 
Somewhere it is mentioned that the ammo spec is well in excess of 1300 fps.
That is above any organization's standard pressure load, the easier adjusted locked dwell time and the lack of an asymmetrical feed ramp will help it handle +P+.
 
gc70 said:
However, the real reason for the rotating barrel is probably lurking in the German police TR/ER "Pistolen" requirements (checklist here - in German).
Click to expand...

Here are a few items that caught my eye while scanning that document, that might bear on why they tried a new design.

Section 2.2 paragraph 3: A tension release [i.e., decocking] necessary for handling of the pistol (including disassembly for service) must be possible without activating the trigger.

Section 2.2 paragraph 5: The pistol must hold up to the firing of a second cartridge when a bullet is lodged in the barrel, without bursting the barrel, action, or grip.

Section 2.4: The forces applied to the hand of the shooter should be minimized by the form of the grip and the center of mass.

Section 2.6 sentences 1-2: For ease of carry, an even, smooth, and rounded form of the pistol is desirable. It shall enable the quick draw from all police-designated containers.

Section 3.1.4: Desired dimensions (uncocked): 180mm long, 130mm high, 34mm wide.

Section 3.2.3 paragraph 2: The grip form should be ergonomically configured so that the pistol lies securely and comfortably in the hand, and sufficiently protects the hand from injury by the recoiling slide.

Section 3.2.6 paragraph 2: The sight radius should be as long, and the height of the sight line as low, as technically possible.
 
My .02, which isn't much LOL! Personally, I can feel a noticeable difference, albeit slight, in recoil impulse between the tilt barrel and rotating barrel design in the multiple pistols I've owned through the years. The biggest difference was in the .40's, with my Stoeger 8040 Cougar having less felt recoil than the Beretta 96 Centurion, which in turn had less than my Glock 23, S&W SW99, and Walther PPQ.

On the 9mm's, recoil feels almost non-existent and shot recovery seems quicker with my Beretta full size PX4 and 8000 Cougar over others in the collection (also goes for the Grand Power I had).

Concerning reliability, I've yet to have any issues with going into battery or feeding/ejection with the various Berettas, but I religiously keep a dab of grease on the locking nub. They just keep shooting well and running like a top.
 
Jim Watson said:
The Savage automatics with only 5 degrees rotation and depending on the Searle Effect to torque it shut a little longer might fall into delayed blowback.
Click to expand...
I wonder if Mete's assertion that the pistol is delayed blowback is related to a failure to understand how the Savage rotating-barrel system differs from the PA-15/Beretta/Stoeger system.

FWIW in an old magazine article about the Savage pocket automatics, I read that then-Col. Julian Hatcher proved that the "Searle effect," as applied in the Savage test pistol used for the famous U.S. Army .45-cal pistol trials, didn't actually delay blowback by any significant measurable amount; IOW the Savage auto pistols effectively function as straight blowback. (The article didn't go into detail and explain how Hatcher determined this.)
 
Searle intended that the Savage pistols function as delayed blowbacks. The idea was that the torque resulting from the bullet trying to turn the barrel (due to the rifling twist) served to keep the barrel and breech "locked" for an instant. I now forget how Hatcher proved it didn't have much effect, but it should be easy with high speed photography or instrumentation, though at the cost of a barrel which would have to have its lug removed. (No, I don't plan to sacrifice a Savage pistol barrel in the interests of science - I'll take Hatcher's word for it.)

Jim
 
The Savage was proven to unlock well before the bullet left by German spark photography is what I've read. My Savages all work well and there's no doubt in my mind that the barrel has to turn slightly before it can unlock.
I also have a CZ24 and in that handgun the rotation before unlocking is more like 40 degrees (Based on memory) so that's a locked breech for my money, I really like both the Savage's and the CZ24 a lot, very interesting handguns.
I have two Remington 51's, the old all steel one's, not the aluminum and plastic one's they sell now.
The breech on a Model 51 cannot open more than about .100", before it does open the slide and breech are locked for a short time, and I cannot understand how anyone can say it's not a locked breech design. It doesn't rotate though but is fixed in alignment.
 
I have four 40 caliber pistols. The one with the least felt recoil for me is the Beretta PX4.

It seems about as accurate as most full-sized service pistols. It doesn't malfunction and feels good in my hand.
 
Styer Hahn Model of 1912 has been mentioned,

https://en.wikipedia.org/wiki/Steyr_M1912

and there is also the Obregon from Mexico.

http://www.gunsandammo.com/handguns/1911s/the-best-45-auto-the-obregon-auto-pistol/

One thing it does is eliminate the swinging link. Back in 1910 everyone knew Browning liked swinging links. Gun designers also knew it was "weak link" Garry James says, in the design.

But not many successful rotating barrel designs out there. Whether that's because of accidents of history or that the rotating barrel doesn't give you much of anything over the tilting barrel, I don't know.

tipoc
 
Oh yeah, the current Chinese military handgun is the CF98, which uses the rotating barrel concept. Supposed to be a soft shooter as all the other rotating barrel guns.

Not that we will be seeing those for sale in the US. But thought I'd mention it.

One thing the reviewer wrote, in Small Arms Review, is that loading the CF98 causes the safety to move to the safe position which automatically decocks the hammer. This seems to be a good idea if one wants to just put the loaded pistol in the holster, and not a good idea if one is doing a reload in the middle of a gunfight.

Bart Noir
 
Gun designers also knew it was "weak link" Garry James says, in the design.
Click to expand...

Odd, in all my years shooting many 1911's I've never known one to break. I agree the link is limiting where a cam is better, but in the 1911 I don't think it can be much better than the way JMB designed it.
 
I'm only familiar with the PX4 but the recoil is about the softest or most pleasant that can be had in a polymer gun, whether 9mm or .40 S&W. Check out YouTube reviews for those or the plethora of guns from Grand Power and watch how they recoil in the hands of shooters.
 
I've held, but never fired, a Savage M1907 in .45.

Supposedly the design made for substantially greater felt recoil than the 1911.

I'd love to fire one, but they are now bringing 5 figures....
 
You must log in or register to reply here.
Back
Top