Paul, my 10 gauge bores measure .810"-.812" just forward of the chamber. Both chokes measure .795". The left choke has obviously been augered out. There are some rough tool marks. The chamber mouths are .855", which would have been the 10A shell. I believe that system was still in place in 1879.

I've been busy - going to Bachelders with Mark [ where I got a 10ga from Mark before he let Brad see it ] and getting ready for our leagues dinner out at the club. Haven't measured the barrels in the "new" 10 yet- but did have to get the right barrel to cock. The trigger was staying up just a hair. The gun had been restocked so I'm thinking the difference between the top tang and the trigger plate was a bit closer togeather causing the problem. Waitng for a top lever spring from Brad- when that comes I'll put it in and class-bed the reciever and stock [ a small gap there ] - remove a dent in the barrel,and it'll be ready to shoot. I'll measure the bore, chamber and chokes to see what they are. Paul

Paul, my 10 gauge has also been restocked. It looks pretty good, but it wasn't mated flush/flat to the rear of the receiver. I will have to do a bit of bedding to fix that. I may also have a top to trigger plate issue like yours.

It would cock both triggers when the stock was removed. It looks like the top tang to trigger plate screw was replaced [ the front one]. All I had to do was tighten it a bit and it wouldn't cock the right barrel because the trigger was pushing the sear up. Paul

Paul and Mark,

I also have a 10ga lifter with 2 5/8" chambers. Made in 1875, it has the step from chamber to bore rather than a forcing cone. I purchased Rocky Mountain Brass at 2 5/8" for loading black powder and they work very well. I wanted to try some smokeless loads, so I loaded Sherman Bell's lowest pressure target load at about 4800 psi in a 2 7/8" shell, and they worked very well. Then I tried Sherman Bell's lowest hunting load at around 5800 psi if I'm remembering correctly. This load in a 2 7/8" shell resulted in tremendous recoil that made it hard to hold onto the gun. I haven't tried that load again because it was unsafe for this gun.
I'm wondering if anyone else has had any problems with longer shells in shorter chambers, or if my problem was a matter of pressure for the configuration of this gun?

Dave

Dave, I have been told more than once that the 2-7/8" RST ammo would be safe in my 2-5/8" chambers because of the negligible step from chamber to bore. When I get around to loading my own, I plan on trimming the Federal hull to 2-5/8" and using Mr. Bell's loading info. My original idea was the RMC brass cases, but with smokeless. I don't know if anyone here has tried smokeless in the brass cases or if it is even feasible.

Paul,

Go back one page and read my post in this thread of 10-13-10.

Think about it. Buring powder produces expanding gas that pushes against wad and shot. If a shooter restricts the path of that wad and shot by shooting a long shell in a short chamber the velocity of the expansion will be slowed but the powder will still be buring and gas will still be expanding. If the wad and shot cannot move forward the gun will move backward producing more felt recoil.

There are a lot of variables such as the thickness of the shell housing and angle of forcing cone but the theory if solid. If one restricts the rate of expanding gas a reaction will be created. All else being equal a 10 gauge produces less pressure than a 12 and a 12 more than a 20 and so on.

If you don't believe me load up some 2 and 3/4" and also 3" shells of the same shot weight and pressure. Then, shoot them is a 12 gauge with 2 & 3/4" chambers. If the gun has sharp forcing cones you will feel a big difference. It the gun has long forcing cones (1.5" or more) then you may not feel much difference in recoil. Chances are any old Parker will have sharp forcing cones.

You could also do the same for your 10 bore using correct length and longer cases.

Have fun!
Mark

Dave and Mark,
I should have added that the advice I was given about the RSTs in my short chambers was taken with a grain of salt. I have never used improper ammunition in any of my guns. It just isn't worth it. I have a nice Lee Loader for the 2-7/8" 10 gauge and plan on taking it from there. I made a 2-3/4" Lee work for 2-1/2" 16 gauge shells, so I think I can make this one work for the 2-5/8".

I have other tens with 2 7/8" chambers. I had purchased RMC brass in
2 5/8" to use in all of my tens. With the Federal hulls, I didn't make the same connection, cut them to 2 7/8", and forgot about the one short ten in the collection. I've read many threads over the years about a tighter gas seal being achieved by a shell slightly longer than the chamber. This is true in later guns with a tapered forcing cone. But, it is not necessarily true in an older lifter that has a sharp step from chamber to bore. This sharp step from chamber to bore was made for hand loaded brass casings of that time. It isn't designed for a longer Federal hull. At the lowest pressures it may work without appreciable increase in pressure and recoil, but in a higher pressure hunting load the recoil may increase drastically. Sorry to steal Sherman Bell's phrase, but this is my version of "Finding out for myself".

Dave

My 10 has chambers for brass I cut my hulls to 2 7/8 then wondered if I should of went a 1/16 shorter to make sure they didn't open and hit the edge of the chamber. Or do you all think it is anything to worry about. If you don't understand my qustion tell me i'll try again. Thanks ch Mark I haven't tried it but I've heard that smokeless in brass don't work to good it seems you need a good crimb because smokless needs to build pressure?