I love my new gun, the M upgrades bring out the full potential of the platform. Well done!
However, in the interest of constructive criticism, the addition of a locking pin to the M charging handle makes reassembly quite difficult. This is a really fussy and irritating engineering solution. I understand why it was done, but why not make a new rear bolt section with a single, threaded hole to accept a threaded charging handle? No possibility of an ejected/broken/lost handle and no chance of installing the handle on the wrong side of the rear bolt. Most importantly, no fussy small part that likes spin on every axis and requires a gunsmith’s touch to orient, align and install properly.
Yes, cost is a factor, but after what I have put into this system, what’s another $40ish for a revised rear bolt that will make maintenance much easier for the life of the weapon?