When I was doing a lot of trap shooting (20,000 to 30,000 per year) I had a pump hooked to a MEC press. BUT NOT FOR LONG!
The noise was terrible, and if something got caught crossways you couldn't stop the cycle of the pump to correct the problem. You push the floor pedal and the MEC completed the cycle. Using arm power, if something got screwed...you stop and correct it and continue.