The AR TDP

[montana]

If anyone is interested I found the TDP for the M-4A1 and M-16 here. Click on Technical Data Packages, Scroll down to find the M-16 TDP

Now you will know if your parts are in spec and within tolerance..https://thegatalog.com/

[LRRPF52]

The M4 TDP is really a great place to start from when looking at 6.5 Grendel, then understanding the specifics of the Grendel chamber, barrel extension, gas ports, feeding cone in the chamber, bolt, extractor, and magazines.