Go for it! I have been using one of Sherman Bell's 1 ounce loads in my 1893 vintage (one iron twist barrels) Baker 10 with outstanding results. I load 22 grains of Hodgdon's Clays, an SP10 wad and an ounce of 7-1/2 shot. A 1/2" thick 16 gauge felt wad, along with a 1/8" 16 gauge card wad, brings the shot right up to the perfect spot for a rolled crimp. The barrels are choked full and full and throw some tight patterns well beyond 40 yards. This load is in the 5000 PSI range. I am loading 2-7/8" shells for the Baker, but will use the same charge in my 2-5/8" Parker. Good luck, and enjoy that 10!
