Re: No big surprise - Burris Signatures slipping on 338 LM
thanks for the suggestions....this is a brand new set of rings with the 4 screw tops per ring, 30mm, Zees. I really didn't expect them to hold forever with the 250 grain 338 load maxed out, but I had hoped they would hold better than they did. Signatures won't hold ANY scope I have tried them with on my .50 BMG for more than 10 shots max, so it wasn't a big shock that they didn't hold with the 338 after a few dozen.
The scope was still slipping despite tightening the screws to the max possible. After about 20 rounds it would move 1/4" forward or more with no more room to torque the screws down.
I replaced the inserts with a new set (they were majorly deformed by the rings by the way, huge grooves pressed into them at the edges) and lightly dusted all the contact surfaces with powdered rosin, torqued the screws to 15 inch pounds. I just went to the range tonight and fired 30 rounds with absolutely ZERO slippage. Once I got it zeroed I fired a nice 5" - 3 shot group out of a cold barrel, at 1147 yards in a 4 mph breeze, just before darkness settled in.