I would disagree that the Grendel based bolt is a common point of failure. Bolt or extractor failure shouldn't be an concern with a properly constructed bolt and when using ammo manufactured to SAAMI specified pressure.
It is true that there were some failures early on with the Alexander Arms 6.5 Grendel bolts, but even those failures were few and far between. I know this as I worked there at that time. I have probably had my hands on more Grendel based cartridge builds than most and have never had a bolt let go on one of my rifles.
There are quite a few Grendel based bolts on the market and some at a low enough price point that make me question their origin of manufacture and potential quality. These I would steer clear of.
I have personal uppers utilizing AA bolts that thousands of rounds on them. The AA bolts seem to be hit or miss on availability. I also have uppers with JP Enterprises bolts and these also have thousands of rounds on them. The JP bolts are more frequently available and I probably just go that route.
