TBA
I've one I purchased pre-owned about 7-8 years ago....an M40A1. It shoots very well but I've not used it a lot or reloaded for it to test groups as you were asking..FYI, I paid about $1700 for it without the scope. I think the new ones now are much more expensive, iirc.
I've no doubt it will make ragged hole groups but can't comment about the 1/4"...
When I installed my scope on the rifle, which came with the TBA rings, I was surprised that the rings were not lapped. They weren't egregiously "off" center or anything, but again I was surprised about this detail...