Started over the last couple of days on a 15 build. I am using a SGT Freedom 80% lower a ?flattop upper and a CNC gunsmithing jig for the holes.Tools are basic hand tools,dremel and a dril press .i have been using the builder squad project info page for starting this. So i have been working on the lipstick/file to fit lower to upper stage ,and i have the following problems.
1]At the rear of the lower where the buffer tube is tapped in,there is a flat plane on the top of this.When i have the upper mounted,i have a rise of 1.5mm appx on the upper where the charging handle goes.Are these two surfaces supposed to be flush?I dont want to remove any more metal as I already have a gap in the rear curvature of appx 1 piece of paper[dunno what that is ,i dont have a feeler gauge small enough to go in.] It isnt bottoming out with the rear takedown pin lug either.
2] Drilled the fnt takdown pin holes in the jig.when the upper is installed i have a gap as well on the ejector side of again 1 piece of paper.On another board it was suggested to ream the holes[done, and use a larger pin].The pin supplied with the lower kit now slides/falls out with no problem.Where do i get a larger pin?Also I have light showing thru in some parts of the upper/lower mating.iwant to keep the tolerances as good as possible.Will this gaping affect the workings,ie dust & crud or have I screwed this up badly and would be better off getting another lower and start again? Or i was thinking of rebuilding the lower where it is gapping with chemical metal and using the upper to impress on the lower,remove and then refile to fit?
help!!!
hinking.gifThanks
Irish