I'm in the process of trying to built my own transfer port for my Cothran power valve on a Mrod build I'm working on. I can build the port fine. What I can't do it get it to seal well. What's the best way to grind out the flat area around the barrel's port in order to increase the size of the oring I can use to seal the TP? I have access to a drill press. But I'm not sure what kind of bit will do this. I do have an old barrel I can practice on.
I just plain haven't been able to build a TP that will seal well in my Mrod. I've tried dropping the power valve into my Flex, but the stock Flex TP is just a hair too long. I don't particularly want to sand the stock TP down to make it shorter, lest I mess it up or decide I want to go back to the stock valve later. I'll probably try to match the stock TP port and just make it a hair shorter. Any particular suggestions before I do so? Ought the TP for the Power Valve be drastically different than the stock Flex TP?