Confused, the 527 has a 16.5mm rail, the 45** rimfires have a 11mm or 3/8" rail depending on whether it is .22lr or HMR/WMR, The Britannia rails for the 527 have 10 grub screws?Tried the Brittania mount with three screw fixing didn’t work to well so I ordered some from America, 11 mm picatinny blocks that had double alan key fixing put them on my 11 mm rail and they never shifted at all, maybe worth seeing if you can get a pair of those first they work extremely well.![]()
