I broke the firing pin and the bolt spring in my M83 .475 LB. I replaced the firing pin and a local gunsmith replaced the bolt spring. The firing pin was most likely my fault as I had just fired a cyl full and dry fired a few rounds and the pin broke (7,100 rnds). The bolt spring broke right at 12,100 rounds.
I have a M97 in .45 Colt. The bolt spring, trigger spring and hand spring all had to be replaced at differnt times. Also had a transfer bar problem that was resolved (IIRC) with a new hammer. This gun had 12,000 to 16,000 rnds thru it when the problems occured, pretty much in the order mentioned.
In a prior post, Mark H. mentioned that the internal springs have all been redesgned and are stronger and less likely to fail. I do keep an extra firing pin on hand for both the M83s and M97s.
FAs customer service is second to none -- they will do whatever is necessary to make sure you are taken care of.
Paul