Ever hear of a revolver that has reduced or eliminated gas loss?

[DG45]

I don't know if this should be on the revolver forum or the Harley Norden forum, but many years ago - and I do mean MANY years ago, I read an article in a gun mag about an inventor - he was a gunsmith as I recall - who was then trying to patent or had already patented an "improved" revolver that prevented or greatly reduced gas leakage between its chamber and its forcing cone. The claim was that such an improvement would increase the velocity of any ammo fired in it beyond what could be achieved with an ordinary revolver.

I figured that anything that could turn an ordinary inexpensive standard velocity 38 Special round, for example, into a 357 level hitter would find a big market.

I don't think I ever saw one of these marketed though. Anyone ever hear of this, or know what happened to the guy or his invention? I'd like to know if it was a bust, or if he was just bought out by the existing entrenched interests and his patents quietly shelved so as not to intefere with their business as usual?

 

[Gonzo_308]

A russian revolver had a sleeve that covered this gap doing essentially what you describe. It was capable of being suppressed.

It would seem that this might overly complicate a fairly simple system and with the increased pressure to make a 38 a 357 you need a stronger gun thereby negating any advantage. I dont see what's gained.

 

[FlyFish]

It was the Nagant M1895. There apparently was a measurable increase in velocity, but not enough to turn a .38 Special into a .357 Mag.

 

[Gonzo_308]

correct, my comment was addressing the op's hypothesis.

 

[James K]

The common Russia Nagant (a Belgian design) does that by moving the cylinder forward and actually inserting the neck of the cartridge case into the end of the barrel, sealing the gap completely. The mechanism, contrary to what some have written, is neither complex nor delicate, but the operation does have an effect on the double action trigger pull.

In a revolver with a reasonable barrel cylinder gap (.006") the velocity drop is only about 25-40 fps. Not insignificant, and equivalent to about one inch in barrel length, but not enough to turn a .38 Special into a .357 Magnum.

In other words, if you have a 2" barrel revolver and want the same effect as sealing off the barrel-cylinder gap, buy a 3" barrel revolver. It's cheaper.

Jim

 

[Magnum Wheel Man]

Also Dan Wesson Revolvers had a barrel & a barrel shroud, with a nut on the end of the barrel to hold the shroud on... the barrel's design was such, that the barrels were easily changable for different lengths... also the owner was then able to set the barrel cylinder gap with a feeler gauge as they tightened up the barrel nut... often the feeler gauge that came with the guns was smaller than what most other production guns set that gap at... however one problem with a tighter than "normal" barrel cylinder gap, is that as the cylinder face got built up with carbon, the forcing cone would start scraping the dirty cylinder face, causing difficulty, until it was scrubbed clean...

if there was a "new patented" design... it may have run into issues around this normal build up ???

 

[Gonzo_308]

Jim, If you actually go back and read what I said, it was that the the idea might over complicate a simple system. I never called it delicate or complex.

If memory serves me correct, the gun was well thought of and considered to be very sturdy.

 

[DG45]

Thanks for the replies. Maybe the guy I was trying to recall was Dan Wesson?

Hi Jim Keenan, are you sure that 30-40 fps would be all that would be gained? I seem to recall having seen comparative stats back 30 or so years ago on 38 Special that used 4" vented barrels vs. 4" unvented barrels to show the differences that would be achieved in revolver ammo velocity if there were no gas leaks - hey! it just hit me that those stats may have been part of the same article about the guy inventing something to reduce gas leaks - anyway I was thinking that the velocity differences shown in that article were greater than that. But it was a long time ago. Could be mistaken.

 

[ISC]

I remember reading an article about the same thing years ago too. It wasn't the Nagant, it was a modern design. As I recall, the revolver was specifically designed to be used with a suppressor and the gas seal was intended to attenuate noise. The idea was to create a weapon that would allow one to kill someone siliently and have multiple shots without leaving any brass behind.

I wonder if anyone's ever silenced a Nagant?

 

[jborushko]

http://world.guns.ru/handguns/hg194-e.htm

http://world.guns.ru/handguns/hg194-e.htm

check this one out! i believe it maybe what the op was looking for

propritary silent ammo too!

 

[Jim Watson]

Or maybe the QSPR on the American side:
http://world.guns.ru/handguns/hg213-e.htm


There was a commercial effort for gas loss reduction and high velocity, accomplished as follows:
1. Assemble a revolver with a .44 magnum cylinder and a .357 barrel.
2. Load ammo in .44 magnum cases with a brass sleeve holding a .357 bullet.
3. Shoot. When fired, the sleeve slams forward against the barrel breech and closes the gap for the .357 bullet to move from sleeve to barrel with minimum gas loss.

Claimed velocity was high, without the case setback worries of a bottleneck revolver chamber like the .22 Jet or .357-.44 B&D. The fired sleeve was supposed to slide easily across the barrel breech as the gun was cocked for the next shot.

The great risk was a careless user loading a standard .44 in behind that .357 barrel. I don't recall the brand name, but it lasted about one gunzine publishing cycle.

(There was a similar setup using bottleneck cases with a plastic sleeve over the neck and shoulder so you could use straight chambers. That avoided setback but had no gas seal.)

 

[DG45]

This may be of interest to anyone who wants to know what that revolver gas leak actually costs in velocity. I just pulled this off the internet. It was written by some guy who patented a test barrel in which the gap could be adjusted to simulate wear on parts. The barrel used in the test involving standard velocity 158 grain 38 Special ammo was 6" long. I assume that same barrel length was used for the other tests, but it doesn't say:

"For example, in firing tests wherein velocities were measured in 6 in. barrels for 0.38 Special cartridges having lead bullets, the velocity measured for a cartridge with a 158 grain bullet, when fired in a standard unvented test barrel, of the type approved and used by the Sporting Arms and Ammunition Manufacturers Institute (SAAMI), was 875 ft./sec. When fired in a test barrel assembly made in accordance with this invention and having a gap between the cylinder and barrel of 0.008 in., the velocity was measured at 780 ft./sec. Thus, the measurement with the SAAMI unvented test barrel was about 12.2 percent higher than the velocity which would result from firing the cartridge in an actual revolver. In another test utilizing a 200 grain bullet, the unvented test barrel produced a velocity reading of 760 ft./sec. while the vented test barrel of this invention produced a reading of 675 ft./sec. In this case, the use of the unvented barrel resulted in a velocity reading which was 12.6 percent high. In other tests, velocities in excess of 15 percent higher than the actual ballistic values have been found in standard prior art test barrels."

 

[Sig_Dude]

I fired a Nagant gas-sealed revolver once, in double action. I *swear* it required like 25-30 pounds of trigger pull...

 

[Glenn E. Meyer]

ISC - I think you are referring to a modified Ruger revolver that was gussied up to use a suppressor.

The gun was written up in one of the Gun Digest company's books on assault weapons or the like.

It also has appeared in some movied and I think in the X-files. It was a 'one of'.

Google might find it.

 

[tenusdad]

My Nagant is cool looking but I think it is a solution to a problem that didn't exist - the trigger pull is p o n d e r o u s........

 

[Stainz]

Here is one of my 1895 Nagants:

A lot happens when you squeeze the trigger. First, the cylinder, a 7-shot, start to rotate. Next, the hammer starts back as the cylinder moves forward against a spring, causing the concave cylinder bore exit to mate with the convex 'forcing cone' on the barrel. As the cylinder - and primer - are now further forward than the frame, or recoil shield in modern DA revolvers, there is a gap - a breech block has moved to the cartridge's head stamp. If loaded with proper 7.62 x 38r ammo, the mouth of the case extends from the concave cylinder bore exit into the enlarged convex 'forcing cone'. This bridges any vestige of a b/c gap making the revolver gas tight - and suitable for use with a silencer, if you can legally do so.

Getting a Nagant down to <20 lbs DA pull requires a lot of cleanup, as the refurbished models often have 'built-up' axles for the hammer, trigger, etc to rotate on. That wishbone leaf spring is too stout, too - some folks have tried ways of lightening it.

The revolvers break down with the removal of one screw - which then traps that wishbone spring for further dissassembly. Ingenious Victorian era design - those Belgian brothers Nagant garnered the Russian army's handgun needs with these revolvers. Try the gunboards.com '1895 Nagant'-specific sub-forum for more info.

The ammo shown is homebrew using modified .32-20 cases - it doesn't 'bridge the gap', although it works well and falls out of the chambers. The right stuff, as made by various Russian military target ammo sources and Fiocchi as well as Prvi Partizan, requires a SA-style ejector rod to knock them out - it's a slow reload.

Stainz

 

[RAnb]

Here is a video I made of my 1895 Nagant. http://www.youtube.com/watch?v=BGoPE7VQ9GY

Yes the trigger is sucky hard to pull, the sights small and the gun under powered. The ammo is some of the most consistent I have ever seen; about 5 fps stdev. I use 1.8 grains of bullseye for 700 fps and 3 grains for 1000 fps. I had to make a longer expander for the Lee die, and add a spacer to the seater to load the proper brass for it, but it works. I use a Lee 30 carbine factory sizer to close the brass mouth enough to make it function reliably. I like shooting it suppressed.

Ranb

 

[James K]

I won't argue with any of those figures, since there are so many variables.

Even with the evidence in front of me (yes, I own a couple of Russian Nagants), I still don't think the b-c gap velocity loss is enough to justify any mechanical means of eliminating it. While I said, correctly, that the Nagant mechanism is not very complex, it does involve extra parts and the gun is harder to use because of it.

BTW, buildup of carbon is not the only thing that will stop a revolver with a too-tight b-c gap. Another problem, less noticeable, is that the cylinder expands lengthwise from heat and a few cylinders of rapid fire can hang the gun up until the cylinder cools down.

Jim

 

[44 AMP]

I see no point in getting worked up about velocity loss due to barrel/cylinder gap. Spending a single afternoon with a chronograph and a variety of guns shooting the same ammo will produce some interesting results.

Sometimes there is only a small difference in velocities in guns with the same barrel length, but sometimes there is a much larger difference. I have even seen 100fps difference between three different 6" guns. 50fps+/- is more common. The loss of velocity between a solid barrel and a revolver is about that, or less.

 

[Webleymkv]

A quick look over at ballistics by the inch can give a good idea of the type of velocity loss you can expect from the B/C gap. Looking at the 125grn Federal Hydra-Shok .38 Special, we see that the 5" T/C Encore Barrel was spitting the bullet roughly 100 fps faster than the 4" S&W 686 was (the barrels are measured differently so you have to select the T/C barrel 1" longer than the revolver you're comparing to). However, it is clear that eliminating the B/C gap isn't going to turn the .38 into a .357 as the Hydra Shok was unable to break 1300fps even from an 18" barrel.