I'm shopping around for an upper, and would liek to be a little more educated, so that as I'm coming accross deals, I know what will fit, what won't, etc...
Lower - RRA
Will Colt uppers, work, or is there some to stay away from, etc... - On a similiar note: will diff brand barrels fit diff. uppers?
dead-on knats ass accuracy is not the main focus here.. Basic function is on a budget is.
Colt made uppers with what are refeard to as large holes. I am not sure of the period but the are not doing it any more. These type would require you to use an adapter piviot pin in you assembly.
Pretty much any upper assembly will fit a lower, there will be machineing tolerances that make some tighter than others. However this will not effect the accuracy of the barrel / bolt assembly.
I would recomend buying a upper fully assembled and headspaced.
If your upper and lower fit is not what you hoped for (too loose) you can use an accuwedge to tighten it up a bit.
I am by no means saying I am an expert, have yet to do my first build but parts are on the way..
give or take, yes any upper will fit.
some require adapters
but all will fit.
OK - easy enough.