Learned a whole lot with this rifle. It started life as a 310 Cadet chambered firearm, and sometime in the 50's I hear, it was rechambered in 32-20. Groove diameter measures at 319", so I'm in search of a .320" bullet mould. Problem is, a sample case expanded with a .320" expander plug was a snug push fit in the chamber.
The 310 Cadet used a heeled bullet like our modern day 22 long rifle cartridges. I guess I could experiment with heeled bullets, but not having done that before, I have a reluctance. I would need to have the heel part of the bullet properly dimensioned to be snugly held by the 32-20 case mouth, and haven't actually gotten my noodle around what those dimensions should look like. Not to mention whether the throat ahead of the chamber will accommodate the bullet, as it might be too long.
However the chamber of the 32-20 is designed for something like .314" bullets, which is what I have cast up so far. I do not expect any accuracy to speak of out of the .319 bore.
I took my RCBS 32-40 expander which measures exactly .320" (it is too small for 32-40 in my estimation, and has been replaced in use with a BACO custom expander plug), and ran it in a 32-20 case, opening the neck to that dimension, plus or minus. It fit in the chamber, but it was a snug push fit. It ejected readily. I did this thinking perhaps I can get a .320" bullet to fit and shoot in the .319" bore.
My current plan is to get a .317" BACO expander and a .320" 110 grain mould made for the rifle, and assemble rounds on those dimensions. The concern I have is the tight fit of the test cartridge in the chamber, and whether there will be enough room for the case neck to expand to release the bullet upon firing. I realize my methods of measuring are rudimentary. I may make a chamber casting to see what we have here.
The only other approach I can think of is to remove the barrel from the receiver and have the chamber neck opened up a couple thousandths to accommodate a .320" bullet.
Suggestions? Ideas?