I am on my third gun now that won't take just any old once fired brass, even if full length resized. All three of em are custom chambers. All three of em take new/unfired brass fine, and have acceptable headspace. I am wondering if small base dies will reduce that last bit of the head of the case so that I can cheap out on some once fired brass!! Maybe I just have to quit bein' so cheap!! What do you think? And BTW the brand of dies is not the culprit as I have tried all brands that are even remotely available, the exception being lyman, as these just don't show up around here much. Thanks in advance .... Marty ...darn I forgot to say that the only once fired cases that won't work are fired from a different gun!!! Those from the piece (s) in question of course have no problems....Later