Obviously I don't know a lot about double barrels and need a little help please is this a 10 or 12 Ga? I measured the barrels at the end of the gun both .771" at the chamber end .882" ID
It is stamped with a 10 here is a link to pics http://imgur.com/a/WIZS9
Also can anyone tell me what the small set screw is for (see pics)

Here's a link to shotgun bore sizes.

http://www.hallowellco.com/bore_size_chart.htm

Nominal bore size for 10 gauge is .775". That tells us that your gun is a 10 gauge. And if your gun measures .771" at the muzzles of both barrels, that tells us there is little, if any choke. I'd immediately suspect that the barrels have been cut. If they have been cut, that will dramatically reduce the value of your gun. What is the length of the barrels?

24" so this means chop chop?

whats a chopped Colt sxs go for?? Its also a little loose when locked can this be fixed at a reasonable cost? That's why I was asking about the set screw I was hoping it loosened the larger side screw that its part of the locking mechanism..........

I always guessed 12 Ga because a 12 Ga shell fit nicely in the gun not loose not tight

The gun in question here has an interesting top tang, quite long, and quite the inletting project for a stockmaker!! I just went through the Colt Model 1878 shotgun pictures on Bing and the guns for sale on Guns International and most Model 1878s have no rib extension, a top tang barely as long as the top lever and early style firing pins. Some guns have rib extensions, some have solid head plungers, and some top tangs are a bit longer then the toplever, some a bit more, but I didn't find any as long as on this gun.

Yes, 24" and no choke means chop-chop. A 12 ga. shell will fit somewhat loosely in a 10 gauge chamber. Have you tried a 10 ga. shell? A modern one won't go in all the way because your gun would most likely have 2 7/8" chambers. If you measurements are accurate, .771" at the muzzles would mean your barrels are at least .043" over nominal bore size for a 12 gauge. This would mean that someone would have had to hone over .021" out of your barrel walls, which might make them dangerously thin, and further reduce value. You did mention in your for sale ad that the barrels are bright and shiny, so I guess it's possible someone honed the crap out of them to remove deep pitting. Hard to tell with the information we have.

I assumed the setscrew you mentioned was a retaining screw for the hinge pin you called a side screw. I don't know for certain because I don't have any experience with Colt doubles. I merely kick myself from time to time for letting a very nice 1883 hammerless Colt double get away from me at a local auction about 10 years ago. It kinda sounds to me as if you have little more than a parts gun here. As such, the value would depend on how many good parts can be salvaged, and then finding a buyer for them. If the barrels aren't honed thin, someone might want it for a Cowboy Action gun.

Something doesn't quite add up here.

If the chamber actually measures .882", a 12 gauge shell will indeed go in... rim and all.

That's 'somewhat loosely'?

How can there be any doubt this is a 10 gauge gun?

I was the one who used the term "somewhat loosely". Discus 420 said, "a 12 Ga shell fit nicely in the gun not loose not tight." It is only because of that statement that there is "any doubt that this is a 10 ga. gun"... and precisely why I suggested he try a 10 ga. shell.

I made my statement without the gun in question in hand. And also based upon a my experience with an H Grade Lefever I bought that was advertised as a 12 gauge. When I measured the chokes of the 28" barrels, they were around .745" and .755" as I recall. But the muzzles did not look thin, so I tried a 12 ga. shell, and it did indeed fit somewhat loosely, but did not fall all the way into the chambers. I then tried a 10 ga. 2 7/8" shell, and it fit perfectly. This was a pleasant surprise because I don't know of any other H grade Lefever in 10 gauge.

As I stated, it would be hard to make an accurate assessment of this Colt shotgun with the information we have. I couldn't get any but the first picture to open until now. It is now plain to see the wide open gap between the cut off barrels.

Methinks the 10 stamped on the web between the forearm loop and the barrel flats is a clue. In looking through the pictures of other Colt Model 1878s on the internet I saw 12 stamped in that location.

https://www.bing.com/images/search?view=...&ajaxhist=0

Keith:

I had a similar experience with a Darne, which was sold to me as a 12 gauge R-10 and turned out to be a 2-7/8 inch 10 gauge instead. At 7 pounds 3 ounces, it's not a gun one shoots with heavy loads, but the RST 1-1/8 ounce loads are a pleasure in it (and the old, no longer loaded, 1-1/16 ounce loads even more so).

It also turns out that 10 gauge Darnes are as scarce as hen's teeth in the U.S. I believe Ted Schefelbein has records of 6, including a very nice one that Tim Carney, who posts here from time to time, took to Africa a number of years ago.

Sometimes seller's mistakes do turn out to be pleasant surprises.

That is a strange top tang thanks for the eyes Researcher I never noticed. I re measured the barrels 10x and the mean is .769 and .765
wall thickness is .055

If I place a piece of .006 shim stock on the water table it locks nice and tight no movement


Keith "I assumed the setscrew you mentioned was a retaining screw for the hinge pin you called a side screw"
Yes the hinge pin will it tighten the lockup?

Lastly would getting a Colt letter do anything except remove 100$ from my wallet??

I found 3 10 Ga that sold at auction all had the 10 stamped on the water table
I found 2 12 Ga both had 12 stamped

As I said, I am unfamiliar with Colt doubles, so I do not know if you could simply turn the hinge pin to move it around to an unworn section, or if you would have to replace it because it only indexes properly at one point. It appears the head is curved to match the curvature of the action bar. But if it is off face, it could likely be removed and welded to build up the worn area. Even if you could turn it, I'd assume there would still be wear in the hook as well. But if a thin shim on the water table makes things tight, it could be that your wear is in the bolting surfaces, even though there appears to be a gap between the barrels and standing breech. Again, hard to tell from this distance.

I think a Colt factory letter is going to be nothing more than a $100.00 expense to tell you that your gun probably came from the factory with 30" or 32" barrels, and has been cut. This is why it is never a good idea to cut down a perfectly good vintage double to make a Cowboy Action Shooter. It absolutely kills the value, and unfortunately, there are already a lot of them out there that are already shortened, if you take the time to look.

In looking at the Colt doubles for sale on Guns International I saw a couple of Colt letters that were pretty nice. The letter the previous owner got for the Model 1883 I have is pretty bleak. It states that the finish is "blue" and that the stock is "wood." The only "blue" I see on my gun is the trigger guard and the top-lever.

Rem40X, I believe that Mr. Carney's ten gauge Darne did not come from the factory as a ten gauge.

This gun has "Doc Holliday" written all over it.

Eightbore:

That Mr. Carney's 10 was not originally manufactured in that gauge probably makes it the rarest 10 gauge Darne on the planet. Not much call for one today and even less for having someone make a set of barrels (or sleeve an existing set) to turn a 12 into a 10.

Beautiful gun though, at least from the handful of photos I've seen.

Rem