I have 2 vintage Tubb grips. They will fit an AR with some slight modification for the safety lever. These have a thumb shelf for RH shooter. Large and Smaller, both are meaty and can have a dramatic impact on your trigger pull and comfort IMO. I have one on 1 rifle already. Tried on a McRees stock but it did not work, AFAIK, you could try to mod. These are dense fiberglass.