Welcome aboard John McLaughlin. I too need to have both knees replaced and wish I could. I've had Osteomyelitis since 1971 and no Orthopedic Surgeon will touch me with a 10 foot pole. How long have you been reloading? What loads have you tried in your 375 H&H? What size groups do you get? At your age, have you considered a scope for it? Due to the versatility of the 375, a number of us have two scopes with QD rings one low power i.e. 1.5 -4 x for closer work and something in 3-9 x or 4-10 x for use at longer ranges.