Is it possible to load 3" 12gage shells with the old mec 250 shotshell loader ? If so, what adjustments, die changes etc. would be needed?

As I remember the Mec 250 was 2 3/4" only. You can load 2 3/4 " on a machine made for 3" but I doubt the reverse holds true. I do not think dies or any parts for that matter are available from MEC. Might be easier to simply go on E-bay and get a new or used 600 jr.. Best of luck

Hey Ruger 4570, thanks for the quick response. I kinda suspected that would be the answer, but you never know. Thanks again.