Good Morning everyone-

I recently acquired this item at the local fun show:







I was told from the seller that it is possibly a 50-95 Express but he had been shooting .50-70 and he had shot close to a hundred rounds of 50-70 with no problem and was getting 2-4" groups at 50 yds.

The action locks up fairly tight, hammers and locks appear to work fine as well as triggers!

Barrels do have pitting but rib and barrels show no sign of separation or weakness. Wood is in great shape.

From what I can tell, the barrels have Birmingham proof marks from between (1875-1887?).

The barrel and one side plate is marked G.S. Abbey, Chicago.

Barrel Proof marks-



Underside of barrels-



My apologies if image sizes are a bit big-
tried to get them down a bit smaller but everything looked distorted!

Any ideas about the possible history or what I might have here is greatly appreciated!

Took her to the range today with my son.
Set up a pie plate at 20 yds and had at it.

Fired off 12 rds.

I yanked the first shot loww, but all the rest were in the plate.

The 50-70 ammo worked great, did get a few keyholes from the left barrel,
but everything went BOOM and hit the plate!

Think I'll keep her!

Have you done a chamber cast to see just what caliber it is?

50-95 has a very slight bottle neck. Did the 50-70 show the bottleneck after firing?
Cal

Thought about chamber casting, but the 50-70 rds seam to fit pretty close.

Fired 12 rds, no sign of any buldge or possible bottleneck.

Fired Cases measured around .542 at the mouth.

No extraction problems. Looks like only half the case expanded at all.

Load was 450 gr lead with smokeless for black.

Cartridges from OWS - supposed to be around 1,240 fps.

Had a nice polite shove when fired. Frankly, it was more than I expected.

I thought the 450 gr at 1,240 would have been almost nonexistent.

If that is a 39 in the picture.
Then 39 round balls of lead will make a pound.
Now you can figure out the caliber.
Or at least the original.

Nitro

Yes, both barrels are marked with a 39 between the proofs.

I pulled this off the internet, if it makes sense:

Caliber to Gauge Conversion A short method for finding caliber if gauge is known involves the use of a constant.
Caliber = cube root ( 4.664 divided by gauge)
Example for a 20 gauge:
Caliber = cube root (4.664 divided by 20)
Caliber = cube root .2332
Caliber = .6155

So the 39 would convert to .493 in.
But the OD dia of the cases mic at .542"
Does that make sense?

Thanks

I would second the suggestion for a chamber cast. British rifles were hardly ever chambered for American cartridges. You should also measure the rate of twist. The gun with proper feeding will most likely no longer key hole and with some patience you can likely get it to shoot a decent group.

Get a chamber cast.
Ask on here for someone who has Bill Fleming's book British sporting cartridges.
It has dimensions of almost all British ammo in the back.
Maybe you can match it to something.
Sorry my copy is packed away.

Nitro

Guess chamber casting it is!!

Certainly don't want to be shooting the wrong caliber and screwing up a good 140 yr old double rifle!

Alright-
Had an adventure in chamber casting-
Got the cerrosafe stuck on the first go round-
had to reheat the stuff and properly grease the chambers and tap after within 2 minutes- but it worked!

Here's the results:
Base = .575"
Neck = .542"
CL = 1.860"
Bore = .504-.507

Rifling was a "ratchet" type with 7 lands.
Right barrel was pretty sharp.
Left barrel a bit less

Both chambers almost identical within .002" or my ability to properly measure.

Barrel twist rate was approx 1/2 turn over 24"
So I figure its a slow twist somewhere around 1:40-46 or thereabouts.

So very close to .50-70 Govt, but... I took the measurements from a 500 3-1/4 BPE round (BELL Brass) and it is closer in measurement when looking at the base dia, neck dia at 1.850" from the base and the rim dia.!

Is it possible that the original chambering could be a very short 500 BPE?

I can literally wrap a 1/4" wide piece of electric tape around the base of the 50-70 govt and still fits the chamber with ease.

Any thoughts?

Thx

Interesting. The rim of the bpe rounds is much more thin than the .50-70. The gov't round will not chamber in a bpe rifle due to the rim. Yes, there are many short .500 bpe made--various lengths. With the dimensions you gave, add the rim thickness and diameter and I will look to my resources.
cal

Cal Pappas-
The 50-70 rim dia fits well.
the 500 BPE rim also fits with a little space to spare.

I have the rim dia from the chamber at around .665 depending on how I measure!

Rim Thickness at the chamber is an easy .062,
Thick rim definitely works.

Rim dia from the 50-70 Starline brass is .650

Thanks