Pretty sure Cpt. Curl had a thread a while back about his 450/400 Farquharson (Army & Navy I think) using pistol bullets.
His is a 3-1/4" but loads and techniques for light loads are the same.
I shoot 400gr cast bullets with 60grs of Varget in mine which is a practice load listed in Wright's book. Shoots well without too much recoil.
Factory loads are quite stiff in a stock No.1. Depending on your hold, you will probably knarf up your right thumb on the safety. There are some good safety replacements out there.
Yes, the No.1 does have more felt recoil more than, say, a 404 bolt gun.