It is a .54.
For those interested here are the assembly tasks:
1. Remove the machining cutter marks from the buttplate and nosecap and polish them.
2. Drawfile the cutter marks off the barrel. Might not be needed if you are browning it.
3. Polish the lock and remove the casting flash. I don't like to see the casting mold joint on parts.
4. Clean up and polish the triggerguard and ram rod pipes.
5. Remove the sharp edges on the sideplate.
6. Install the latch on the patchbox lid and file the catch step to make a solid catch on the buttplate. I also bent it some more. As received, it didn't latch up very well.
7. Remove the trigger to round and polish the top of the bar. Not really needed, but I didn't like the sharp corners on the top.
8. Fit the nosecap and put screws in it.
9. Install sights. I replaced the back sight for a higher one.
10. Assemble and taper the ramrod. After assembly, I just stained it and waxed it.
11. Sand and finish the stock.
12. I used brass black on just about everything to color the brass a little.
13. Final assembly. Drill out the too tight pin holes and install the pins.
