I have been waiting on my 617 for months for my dealer to get one in. well he finally got one in yesterday so i jumped on it. after getting it home i proceeded to load up some S&B 158 gr .357 and do some practicing. On 5 of the chambers it functions great, on 2 it will not rotate at all. I tried some UMC 38 and some Speer Lawman 38 and all 7 fired great. any ideas on what could be wrong?