Hey all,
I have a Model 1 upper on a DPMS lower. The take down pin is snug / just right passing through the lower with the rifle broken open, but binds up pretty badly when passing through the upper.

I've tried polishing the hole in the upper and polishing the pin, as well as generous lube, but I still have to use a punch and mallet to move the pin through the upper.

Any advice to offer?

Thanks,
tt

Tried pushing in the rear pin then the front pin?

Quoted: Tried pushing in the rear pin then the front pin?

Should have before. The front pin is very tight too, so I've simply been shotguning the rifle open for cleaning and such. After reading your question and slapping my forehead, I tried it. With the front pin withdrawn, the rear pin will insert by hand up until the last 3mm or so. So, it looks like a slight difference in the space between pin holes on the lower and the upper preventing them from lining up together, right? Is this an unresolvable issue?

Unresolvable depends on what is causing the mismatch. If you have the skills strip the pins from the lower and set the upper on the lower. Look through the holes and see what direction which set of holes is out. Sometimes there area of the upper over the mag well has a high spot that can be taken down. Sometimes the top of the lower near the pivot pin is too high. Sometimes the pin holes are just out. Each can be fixed.

I have two Model 1 uppers and have had to fit both to my SGW/OLY lower. Usually taking some material from the pin hole will be enough to get everything to line-up. I always make the adjustment on the Upper Only, by using a dremel and taking off a little material at a time until the pin slides through with just a bit of resistance.