I had an 1850's percussion sxs that was originally proofed 9/10 gauge but the barrels had been honed over the years so when I got it they measured 8.5/9 gauge. Old percussion guns often had slight differences in the gauges between barrels. I decided to shoot it with a standard 12 gauge load of 3 drams BP and 1-1/8 ounces of shot. However, knowing how easy it is in the field to accidentally put two loads of powder in one barrel, I loaded each barrel with 6 drams BP and the same 1-1/8 ounces of shot. I strapped the barrels to a sawhorse put a piece of cannon fuse down the percussion nipple on each barrel and one at a time I lit each fuse while I stood safely behind a tree. After an impressive amount of shock and awe I was delighted to find the barrels held together just fine, no worse for wear!
Here's picture of the gun with its first pheasant.
