Wealth of info here that I'm glad I came across....I’ve been building and working on guns for quite some time ... built some custom stocks over the years and I've come across an issue that I thought I’d run by you guys for some input. This group appears to have some seemingly bright folks. I’ve done a fair amount of reading and research regarding AR10/LR308 trigger locations relative to the safety selector switch. I’m one of those guys that bought some 80% lowers about a year ago from a company that does quite a large volume in sporting goods and is owned by a very grandfatherly looking guy that seems genuinely interested in your well being. (at least on TV he comes across that way) ..... but, I failed to measure them with any accurate degree when I receive them. They looked great and with a new factory anodized finish I simply checked to see that they were all intact and undamaged and put them away until now. (My mistake and lesson learned) I have a shop with a mill and other machining equipment that I’ll be using to finish these up but as many of you know already some of these lowers have the selector detent channel about .049" closer to the forward take down pin than it should be. Filling and re-drilling or enlarging or modifying the grip (for the spring hole) is not a big a deal and in my case it’s really not since I’ll be building all custom wood parts for this rifle, but as some have suggested filling and re-drilling the detent channel seems like a major PITA.
I also have read where folks index everything from the safety selector detent channel so the selector works correctly but I question this practice as this will this push the entire fire control group forward .049 inches which then would change the relationship between the bolt, firing pin, and hammer. Maybe this isn’t a big deal but when looking at another rifle I have, it looks like it could be a big deal. I also could mill the hammer and trigger pocket and pins in the correct location relative to the front take down pin and simply move the selector hole to line up with the detent channel but that would put it fairly close to the disconnector of the trigger assembly (.043" gap) and not sure that crowding this is a good idea either. Maybe splitting the difference by drilling the safety detent selector hole in line with the detailed channel and shifting the trigger and hammer pins and pocket forward a few thousands to gain a little more clearance at the disconnector but still not create issues with the bolt.
Thoughts ? ... and if this question should be in another section feel fee to move it.