That sounds more like a Diameter problem than a length one. Assuming the 2 3/4" shells are fold crimped & the gun has 2 9/16" (65mm) chambers there should be absolutely no problem encountered from the length in chambering them.
Have you already tried the RST's, unles they are a little slimmer you may well encounter the same problem.
Chamber itself may have been reamed under present minimum size.
PS; You did mention you used reloaded shells. Were those hulls possibly fird in a "Loose" chambered gun. They may be running oversized. I have encountered this in using hulls I had picked up which were fired from an Auto-loader. Some of these seem to have "Generous" Chamber dimensions.

Last edited by 2-piper; 05/25/10 10:29 AM.
Miller/TN
I Didn't Say Everything I Said, Yogi Berra