Originally Posted By: cayotehuntermy other lower is a PC lower and that shelf is much lower. The DPMS lower just barely doesnt fit, maybe a 1/16 in lower shelf my upper would fit. Would it hurt to try and file it down just enough for the upper to clear? I would only try that as a last result if DPMS cant do anything for me.
This just my two cents. I would not want to modify my lower. I would trim the upper post before trimming the lower. That shelf is one of the parts of your lower that you would have to modify to make it accept a m16 trigger group. You could also email the ATF and ask. If they respond that you can modify the lower, keep a copy of it
