I have a receiver set Im working on.
I just started assembly and the upper and lower fit it too tight
The only way i can get the pins in is to put the front one in first then close upper and drive the back one in with a punch
It will not go together by hand
Upper is Mur with a gen 2 noveske lower
I tried the upper on a different lower and it fit so I think it’s the lower
Any suggestions to lossen it up enough to assembly and dissembly more easily ?
They’ll loosen up over time with use. Keep the pins lubed & work then in/out a bit.
Not the first time I’ve seen a tolerance issue with Noveske lowers.
What Lower Parts Kit are you using?
I just built up a Noveske Gen 2 with a DD LPK.
The FCG pins were nearly impossible to get in.
Which part was out of spec?
I’m presuming it was the lower. I’ve never had a problem with DD LPK’s before.
I’ll know for sure when I put in a Geissele.
I have Noveske MUR and Gen2 lower that have fit perfectly from the beginning. I’ve heard about tight fitting Gen2’s though.
Give it some time, it will loosen up.
Me too. I have or have had four Noveske lowers, every single one with some kind of fitment issue.
I have four Noveske lowers that are perfectly in spec and mate up with MUR uppers with no issue, but that doesn’t do anything to help the OP. There is as much or more of a chance that the take-down pin in the LPK is too large, but measuring the pin and the pin hole is the only way to pinpoint the issue. The LPK has not been identified yet, and that could reveal a lot.
I also have had no issues with the Gen2 noveske and MURs. I did just assemble a BCM lower on a MUR last week and had to tap the rear pin in with a small rubber mallet. And to get it out a small punch and tap a few times. I prefer this fit at the start. It loosens up after a while, while maintaining no slop. I will be happy to take all of the Gen2 noveske lowers off peoples hands that are too tight 
Is the upper closing all of the way? If you snap it shut does it stick trying to open it? If it does snap it shut and bump it open 3-4 times. Is the rear pin still tight? It shouldn’t take more than a light tap with a plastic faced hammer to get it in.
I have a DD kit on my Gen2 lower also. I called DD and they sent me another set of pins free of charge. They fit snug but nothing I couldn’t remove by hand.
I think the pins are from a palmetto state extra lpk
I do have the battle arms pins enroute and are what I was planning on using
Like others have said, they’ll wear in eventually. If you’re really concerned (others will probably jump on me for this) about it, trim your detent springs by a few coils or if your takedown detents are a little sharp, knock a little tip off with a small hand file and smooth it with some 600+ grit sandpaper. That’ll loosen it up for you. Just don’t clip too many coils or you’ll have loose takedown/pivots pins. I admit to doing this once or twice and it doesn’t seem to hurt anything. Remember to measure twice and cut once.
I would try some of the Noveske pins, the lower may be a better fit with them. I’ve been finding out the hard way one manufacturer may machine parts at the small end of the tolerance range, or just the opposite. When tolerances start stacking up, problems occur. I have a Bushmaster lower that every upper I have fits on, but uppers rattle on it. The Spikes and Aero lowers I have are just the opposite, some uppers are just too tight.
Don’t jerry rig the weapon like this unless its an ipsc gamer gun and not for serious use…
My Noveske gen 2 ffl fits it’s MUR upper like a square peg in a round hole. Extremely tight and requires some light tapping. Hasn’t loosened up yet and it’s seen use. Always thought it was my own strange luck.
Ive got a Spike’s lower and DD upper that are really tight. Nobody I know can get the takedown pins out far enough without tools (the tip of a bullet) to get it separated. Both fit fine on my friend’s uppers/lowers so I attribute it to tolerance stacking. Not a big deal, got a few thousand through it and it hasn’t loosened up in any appreciable way. I actually do not mind at all as there is literally 0 slop whatsoever and it makes my buddies jealous lol.
I would wait for those BAD pins to arrive, and then try it again. Parts are not just parts. I have the BAD pins in almost all of my lowers, and have not had any issues.