Hey guys,

I just got an NDS retro lower to complete a 603 build I'm working on and when I test fit the upper and lower the fit is pretty tight. The upper and lower have to pressed together ever so slightly as if against a spring.

it doesn't feel as though anything is going to break but there is definitely tension on the front pin. Anybody else who's built on an NDS lower run into this?


Looking forward to responses.....,thanks guys.

Yeah, they're tight. On purpose as I understand it. Mine work just fine.

Yes, I have. For the 603 in my avatar photo, I sent my upper receiver to NoDak and had them fit it to a partial fence lower receiver. The fit was extremely tight to the point where I had to have a tool to push out the rear takedown pin, but over time, with lots of shooting and disassembly, it's perfect. There's no wobble between the receivers, and the takedown pin can easily be pushed out with my finger. For my other 603 (613, actually ) I sent them that receiver as well, and it was perfect from the get-go. No wobble between the receivers, and the takedown pin is easy to remove. I haven't even shot that rifle yet. I'll say that if you can slide the takedown pin in (not back out) with no hammer or anything of that sort, you'll be fine. However, if you have to hammer the takedown pin in, the fit between your receivers is too tight. That's just my opinion.

I have several and they all are tight. "Tight's just right"

Excellent gentlemen...thank you all for the fast replies. you are why AR15.com is THE BEST.

Open this thread,scroll down and read Mike_nds sig line. http://www.ar15.com/forums/t_3_123/544218_HandR_upper_question_for_the_Retro_hive.html

Funny you should ask. I just fit a  PM A1 upper to my latest NDS-A1 lower. I just took a little material off the rear of the upper.

The upper wouldn't fit well on any of the 4 NDS lowers i have on hand.

My CK A1 upper fit perfect on my 2nd NDS-A1 lower, and my first NDS-A1 lower came as a matched set with the upper. Both are snug.

I love NoDak Spud.

FWIW, my 1966 vintage XM16E1 upper is very tight on the first lower I bought from them (partial fence) but when I put a Colt A2 M4 marked upper on it (excellent condition BTW - hard to argue issue with lugs) it fit perfectly - snug fit but I can push the takedown pin in and out much easier. So is it the upper or the lower? I like the fact that Nodak has such tight tolerances. You can always loosen it up, but going the other way is tough. That's why they make shims for AR receivers to increase accuracy.

All of mine fit tight as well, never been a problem though.

I have 6. They all fit that way at the beginning, although after 400 rounds, the fit on the .458 Socom is starting to get not quite as tight, although still better than some more modern stuff I've owned.

Tight like you describe is good. There's a little flex built in.

This is copied directly from the NDS site!

A WORD ABOUT THE FIT OF OUR LOWER RECEIVERS:

OUR LOWERS ARE MACHINED IN SUCH A WAY THAT THEY HAVE A TIGHTER FIT TO MOST UPPERS.

WE RUN ON THE HIGH SIDE OF THE TOLERANCE,  WE DID THIS ON PURPOSE.

99% OF THE TIME IT RESULTS IN A GREAT FIT WITH NO WIGGLE BETWEEN THE UPPER AND LOWER.



SOMETIMES THIS MAY CAUSE PROBLEMS WITH SOME SURPLUS UPPERS OUT THERE.

IF YOU ARE CONCERNED THAT THIS MAY BE AN ISSUE FOR YOU, PLEASE PURCHASE ONE OF OUR RETRO UPPERS AT THE SAME TIME, AND WE WILL HAND SELECT THEM FOR FIT AT NO EXTRA CHARGE.

IF YOU ALREADY HAVE A STRIPPED UPPER YOU WANT TO USE ON ONE OF OUR LOWERS:

YOU CAN SEND IT IN (AT YOUR EXPENSE) AND WE WILL MATCH IT FOR BEST FIT IT TO THE LOWER YOU ARE PURCHASING FOR NO ADDITIONAL CHARGE.

WE JUST WANT YOU TO BE HAPPY!  

Oh Mike... you're such a tease..   he he he

I like the way mine fit;  all four of them

Count your blessings.  My service rifle (target gun) is built on Rock River upper and lower receivers and it was a loose old bitch from the get-go.  Doesn't seem to affect accuracy any, but, all the rattling and flopping around is disturbing.

i just put a a1 together and was nice and tight. im very happy with the fit and mine was a blem lower.