I recently acquired the .55 Boys round shown on the left in the picture next to a .55 Boys W1 AP round. It appears to have a copper washed case but is H/s ‘K39. W1’. I have weighed a W1 AP round which comes out at 2020 grains, this includes a 186 grain propellant charge. The copper washed round weights 2045 grains. According to Peter Labbett proof rounds were charged 220 grains of cordite. So the difference is 2045 -2020 = 225 grains which suggests it is a proof load. Labbett states proof rounds were copper washed and H/s with a Q. I have never seen a Boys proof round, does anyone have one, or has anyone seen another copper washed Boys with a W1 H/s which could be proof? Thanks in advance.
.55" boys proof rounds were usually marked with the Q proof letter
I had a proof load (but traded it to Bill Woodin as he’d never seen one). Picture below.
With the copper washed case and weight, I’d be inclined to say it’s a very early proof, despite the lack of correct headstamp.
Thanks Tony and Paul, on rechecking the weights of the projectile I see that they did not use the W1 projectile in the proof round, so my calculations are out. That said the case is, in my view, clearly ‘coppered’ so maybe as Paul says it is an early proof.
Paul thanks for the pic of the Proof Mark III a very rare beast.