Customer brought in a Hopkins and Allen single shot rifle. Only markings were the company name/city and .25-20. He got some .25-20 rounds made by PCI Ammo (new brass, 90gr Bear Creek FP - unknown powder charge - customer is going to try to find this out). Fired one round and called me.
Here is side by side picture of the fired and unfired rounds. On the left (where the bulge of the one on the right starts closest to the base) measures 0.304. The bulged case on the right measures .352
The measurements of the unfired round match what I could find about the .25-20 SS round.
If I drop an unfired round in the chamber, it goes in further that it should, it goes in well past the extractor and when you close the action the extractor goes over the base not under the rim of the round. The chamber apparently is too large a diameter. The customer wondered if there was supposed to be a "sleeve" in the chamber for the .25-20 ss round but I couldn't find anything that said there should be. Examining the chamber, there are no markings that would tell me that a sleeve whould have been placed in it. That said, the bulged case diameter is close to the case diameter of a .25 WCF. Might it be that someone at some time rechambered it for .25 WCF? I'm going to get the rifle back in the next couple days and do a chamber cast to see how it measures out.
Thoughts? This rifle is in very good to excellent condition. The barrel/action has been (very well done) and it seems to be a good solid rifle, abet not as a .25-20 single shot chambering.