Can anyone share some wisdom on this topic? Their web site says it is to be expected that either the rear pivot hole or front pivot hole MIGHT needs fitting to a specific lower.
Mine is not closing all the way, and the interference seems to be the rear of the Big Hole upper contacting the area of the lower where the buffer tube threads in. A sharp blow with my hand achieves closure, BUT the front pivot pin is then tight as can be, won't rotate at all, and I fear a strain is being caused at the front lug area.
The "fit" issue is identical with a s/n SP636xx and SP1730xx lower. Should I "adjust"(aka file) the front pivot hole in the upper? Or remove material fron the rear edge where it is hitting the lower when forced closed? Send it back and hope for a better match with either of my lowers from another production run? The color match is great, and other than the fitment issue the machining and finish appear to be first class.
But this binding and difficult closing issue is making me think that my old adapter pivot pins weren't that bad afterall. I intended a high end SPR style build for this upper, and am now hesitant to proceed. Shipping one of my "babies" off for fitment is out of the question, I need to correct this locally if at all possible. Suggestions?
Comments from posters who have NOT actually used one of these are NOT being solicited.
Paladin