doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com Will this work?

I have an old Lefever, damascus barrels that I am restoring myself. I have been thinking about a double rifle. Not for dangerous game, mainly deer, etc.

I also have a set of 12 gauge 18" inserts for 45-70 from MCA Sports http://www.mcace.com/shotguninserts.htm

My question is this. Will the Lefever handle the back pressure from a 45-70? I know there are other issues, such as extraction and regulation, but before I go any further, I thought I would ask.

Thanks,

Pete

There are .45-70's and then there are .45-70's! If you're planning on using loads designed for the Springfield then I'd say you will be ok. If you're talking about loads designed for the Ruger then I'd say NO WAY, in the old Lefever action. That action was never designed for pressures like those.

Ron,

I intend to only load low pressure trap door loads.

Pete

The logic that I have used as a guide for action strength was to multiply the cross sectional area of the shell it was built for times the working pressure of that type of shell.
Do the same for what you intend to shoot and see how the numbers compare.
For example a 12 guage at 12000 psi (guessing a base diameter of .8) works out to just under 7700 I think. A 45-70 base of .502 and black powder pressures in the 25 - 30,000 range gives about 7500 units.
In other words as long as you stay below roughly 30,000 psi loads, the thrust on the breach face should be roughly similar to modern shotgun loads. On the other hand load the same shell up to Ruger #1 pressures and you will almost double the thrust, at least in my opinion.

cheers Doug

Thanks Doug,

I will be keeping the hand loads at around 25,000 to 27,000 psi. I have killed boar and deer effectively with this load. (50 grains of imr 3031 behind a 405 hard cast flat nose.)

My concern is the strength of the Lefever. I have no idea what pressures they were built to handle. 12,000 psi seems high to me, but I could be wrong.

The problem I have at the moment, is that every thing I can find focuses on the damascus barrels. With the inserts, they are no long a factor, so my focus is on the breech.

I believe that the breech will hold up to cowboy loaded 45-70's. I am just looking for some more proof.

Pete

I am not an expert, but I understand that the brass case contains the pressure at the chamber. Barring a ruptured case, you should not have a pressure problem.

Actions are cracked by backthrust, not by pressure. Your gun, if otherwise in good condition, should be safe with inserts.

That's my opinion anyway.

My comments on action strength deal with thrust not pressure. The significants of pressure however is that the cartridge when fired, is in effect a piston of x diameter and y pressure and the thrust is a multiple of the two.
Looking at my Lefever, it is not an action that I would want to subject to very high thrust. Perhaps I am just predjudiced by I guess that I feel that a lump with a notch in it, held down by a sliding bolt is much stronger than a top rib extension with a notch etc.
The counter point I guess is that about 1/2 of the thrust perhaps more would be taken by the hinge pin and that on a Lefever is similar in strength to many other shotguns
In terms of working pressure, I think that the locking mechanism on Lefevers survived into the smokeless era hence my speculation about working pressures on a 12 guage smokeless shell.

cheers Doug

I cant help with the pressure; but Ive been pondering the same idea for more than a year. Ive got a couple of Stevens 311's in pretty decent shape that are just screaming for a workout; but I cant seem to get a response from MCA. When did you get your inserts. How are you planning to remove the fires cases?

Gentlemen,
I have lived long enough to have seen a double shotgun gun convereted to a double rifle. It was an L. C. Smith. The fellow built a pair of barrels chambered in 30-40 Krag. He did a beautiful job. The receiver of the gun cracked and one lock plate was practically blown out. Nobody was seriously injured. There were two problems. One is that the action was never meant to stand the pressure of a rifle cartridge of that type and the other was the firing pin hole was a little to large for rifle pressure. In most shotguns the openings are pretty generous. The primer blew out around the firing pin into its opening. This especially true in the Stvens 311 and Savage Fox model B's. Be careful!
You might save up and buy one of the replica double rifles in 45-70 caliber. There you would not to worry about losing an eye or part of your face.

Having been an avid shooter for nearly 50 years I have seen Damascus Barrels 'give' even using low pressure black powder cartridges.

No reputable gunsmith will touch a Damascus barrelled shotgun these days. They were good in their day, but that 'day' was a century or more ago. If you look at the way they were made you will see the inherent dangers, a long thin strip of metal wrapped around a former and the edges hammer welded together. All sorts of impurities could be in the welds and none of it visible to the naked eye.

My advice is to deactivate it permanently, and use it as a wall decorator. A couple of friends of mine wish they had heeded my advice, they are both now missing fingers.

They stopped using Damascus barrels at the beginning of the 20th Century. Ask yourself why?

Shoot well, shoot safe, it's no pleasure shaking hands with a guy with only a thumb left on his hand.

Harry