.50 reloaders for single shot or semi auto

recently picked up a Serbu RN50 break action Rifle, got a very nice deal direct, with military discount. Only question was-What to feed it?
Been looking around, and found some 635gr API (Yes, Armor Piercing Incendiary) for under $40/100 bullets at the Ammo store-was hoping to find Wes had something (Maybe soon?)
So I got a $400 Lee Press/die set, and proceeded to try it. (Been reloading for 35 years, so WN?)
The primer pocket is crimped, so I had to trim that, Then had to use the Broken(yep, after 4 rounds!) primer punch, cut off, to slightly open the primer pocket-the crimp was THAT Deep!
The primer system came with the press-and jammed after 6 rounds, forcing me to remove a Live Primer from it 4 times before it became completely unusable. "Viola"! RCBS priming tool #9560, and now all my primers look like Factory!
Took it out with a Gel-Pad on the buttstock, and made the Classic Mistake-Never raise your rifle high enough that your Chest is off the Ground!
4 Dislocated Ribs, broken Xzyphoid process (the bone/cartilage on the bottom of your Sternum).
1 shot, destroyed the solidified bag of Concrete completely.
Fired it since, and never had another problem (been23 years since I fired a 50 in the military, so I had to re-Remember the Respect that weapon Demands!)

Anyone wants help reloading 50, give a yell-you can Avoid my mistakes.