I bought an 80% NFA glock 9mm lower a year ago, and haven't done anything. I want to make a cheap plinking rifle. Currently, Daytona Tactical has $70-80 16'' 9mm barrels. I want to make it reliable, and have heard of problems about the bolt catch breaking, and about problems with the buffer area. How can I overcome these problems on the cheap? Currently my plan is to use a forged upper with the half sized port (is this even needed?, should I just use a slick side), the PSA 9mm Buffer, and a PSA 9mm BCG.

the standard New Frontier/PSA lower should not have a LRBHO option as the Glock mag versions typically operate off the front of the magazine follower and need proprietary linkage to the bolt catch, as opposed to the Colt clones that use the Colt mags designed to operate the bolt catch off the back of the follower... you will still have manual bolt hold open to clear the carbine...IMHO the cheapest option is to buy a complete PSA upper with bolt and charging handle and a pretty nice MI fore end...I pieced together my first 9mm upper, but have replaced it with a complete PSA upper on a NFA lower... nicer fore end and tighter upper to lower fit

I had to ream the throat area of my PSA 16" for 1.130 hand loads... but did not for my 10.5 barrel  ....I built my PCC for USPSA with a rifle length stock and buffer... used a variety of heavier buffer weights, but went back to a stock 5.2oz rifle buffer and rifle length spring.... my SBR runs on a H2 and Colt mags with a Macon Armory bottom load mag block... good luck