Bryndon, the first thing you need to do is to slug the barrel. It should be around .450-.458". Huvius is probably correct that it is indeed the Westley Richards No.2 Musket but according to Kirton's book, the only express model listed is in No. 1 Musket which is shorter. Can you do a chamber cast?
I doubt that Gander Mtn is going to have ammo for this as I don't think any has been loaded for some time. You may find some Kynoch around at a gun show but it will be very spendy and probably Berdan primed. It's interesting that your gun has Henry rifling as I have an 81' with Metford rifling. Mine is a target version and I am curious to know if WR used Henry rifling in the express models and Metford in the target models.
The WR #2 was originally loaded with a 480 gr .451" diameter bullet wrapped to .458" with paper. I believe there is a picture of it in Kirton's book.
Now the good news. If it is indeed a No. 2, brass can be formed from .50 cal basic brass. This is available from Buffalo Arms. Dies are available from CH4. That way, you can use LR primers instead of Berdan. Are you intending to load black or try smokeless?? Bob
