I've used these for years on my MECs, but recently have been having trouble getting them to hold the settings...even with the set screws dangerously tight. Anyone else have problems with them? I'm considering going back to bars and bushings.

It's a love hate relationship with the UCB; some people love them while others hate them. That said it's important to approch a setting on the UCB from one direction per the instructions. You will find that there is a bit of "play" in movement of the bar if you do not, this leads to some drop varation. Another thing that will help even out those drops is to ground the machine to bleed off any static if you have dry air & static build up. Wiping down the powder bottles with a Dryer anti-static sheet helps quite a bit too, cut some strips and put them inside the powder bottle and shake well. Lastly try the Red Plastic Powder Baffel, forget the pot metal one that comes with the UCB bar. The Red Baffel works great and helps a lot to even out drops, prevents powder leaks and eliminates the washers under the MEC bottles. You do not say which gauge your are loading. I had difficulity with using a UCB on my MEC 600 - 28 ga as the square UCB opening for powder did not align well with the round MEC drop hole. I ended up going back to the OEM bar and bushings and only use UCB's on my 12 & 20 ga machines.

Thanks, ScoutMaster. Actually, the only one I seem to have trouble with is the one on my 28 gauge press. The ones on the 12 and 16 gauge presses have given me no trouble.