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.
