New to the AR section, but not real new to the FTF forum. Well here I go again. A few years back I built a Post Ban Carbine. COOL little shooter but turned it over for a VERY good price. Had about 600.00 in it and had a guy, who could legally own it, offer me double that so I said what the Hell. Not sure WHY he wanted it so bad, and pay that price, but that was 5 or 6 years ago and he hasn't been on the evening news, YET. A friend has gotten me back into the AR mood. So I went to a local Gun Show, Louisville, KY btw, and found a VERY nice lower made by Accurate Tool in Lexington, KY. The final details of their process resulted in a gorgeous lower that is DEAD ON Mil Spec. Not to mention, Home made. Not sure where they get their castings, or if the are made in house, but the final product was the best I saw there. Then found a cute little, and I do mean LITTLE carbine upper assembly (10.5" barrel). Turns out it was too short of a barrel for me to use with out a bunch of additional paperwork that I don't want to apply for. I was a little pissed at the guys at Double Star Corp, from Winchester, KY, for selling it to me. I will assume the responsibility for the purchase, but I was there haggling with them. Purchased a Socom collapsible stock and they knew what I was building and NEVER said anything about needing any special paperwork for that barrel. I installed on the Lower and OH MY GOD!!!!! the fit was HORRIBLE!!!! Looser than a .50 cent hooker. I could not believe the fit. A PAIR of Accu Wedges would not have helped. Like I said the Lower is DEAD ON Spec. The pivot and take-down holes on the upper calipered at .258" and .259" respectively. I called Double Star, and the sales guy remembered me from the haggling. Said for me to send it back. Said he would spend as much time as needed to find me another M4 Flat Top Upper with a 1 in 9 , 16" barrel with an A2 front sight and flash hider. Said they would refund my shipping if I put a copy of the UPS ticket in the box. So far they get an A+ for the customer service on the exchange, but Not sure I should have gone through this step in the first place. The new upper should be here today. I can't wait to see how it fits. I have an OLD, VERY used Colt Preban HBar 1 in 7 NATO A1 upper on it now (With the offset bushing in the pivot hole) and it is tighter than a $1,000.00 hooker. Even without the bushing in the pivot hole, the rear take-down pin is VERY snug and aside from the color mismatch, looks and fits like a matched set upper and lower. I will try to get some pics of the lower and stock assembly for ya. See Below As far as innards on the Lower, went with the standard DPMS lower parts kit, for now. I plan a Yankee Hill free float forend and all kinds of other goodies, as the budget allows in the future.