Mike,

I don't know if I would say you could shoot it "all day" without discomfort, but certainly you could fire it considerably longer than you did, I would think. Training really isn't necessary, just a little practice. If most of your shooting practice to this point has been defensive in nature, or if you fire semi-autos most of the time, then that might explain why your .44 is hurting you. In defensive practice or in shooting semi-autos, we keep our arms and wrists fairly stiff so as to stay on target for fast follow-up shots or, in the case of semis, to keep from "limp-wristing" the gun and thereby cause cycling problems.

With large caliber magnum revolvers, we want our elbow bent somewhat and both elbow and wrist slightly relaxed, allowing them to flex when the gun recoils, thereby allowing the recoil to take the gun upward and backward without jarring and twisting in the hand as much as it would with our arm in a straight, stiff position. If you've seen any of the Dirty Harry films, Eastwood appears to have mastered the technique(whether the gun recoils as heavily with blanks or not, I don't know). When he fires his 29 in those films, it very much resembles the movement I've experienced with my .44, and it doesn't really cause much discomfort at all.

As others here have indicated, sometimes a different grip helps. But I think I would try the above technique and see if it doesn't help some. Then if you're still getting hurt by the gun, try a different grip.

Best wishes,
Andy