Magpul ubr + delton lower = problems
 

So yeah, I just spent $270+ on a part I've been dreaming about forever. The Magpul UBR stock. And I have absolutely no complaints about it at all. But my delton lower is a piece of non-mil spec crap. The ubr doesn't fit properly and leaves a gap between the lower and the main tube assembly on the ubr. So my dreams were a little crushed. But, I figured I've been needing to buy a new stripped lower for quite some time, seeing as my pmags don't drop out of the magwel and installing a miad kit required alot of force and a dremmell. My dad's friend showed me his Spike's zombie lower awhile ago and I want that. It's affordable at $115. I just wanted to tell everyone that delton needs to get there stuff together, and ARE SPIKES LOWERS MIL SPEC?

Btw the ubr will still function on the delton lower. The only problem is that because of the slight gap, it takes a little tension off of the rear takedown pin detent spring (which I broke during disassembly). So your rear pin will be a tiny bit looser.

Idk the proper term for the hole in the lower that causes the problem, and I'm too lazy to google it. But it's the small circular hole cut into the outside of the lower right under we're you screw in the buffer tube. The ubr main tube assembly has a circular piece that fits directly into the hole and keeps the ubr from spinning around. Delton made the hole too small and the ubr won't fit in. It sits of the edges of the hole but not in it.

Yes spikes are mil-spec. They are a bit tough to get a hold of at the moment though. I've been keeping an eye out for a punisher lower for over a month now. They come into stock and sell out in a matter of minutes.

the ubr requires a shorter than carbine extension called an entry length extension tube that should have come with the stock.

I know that. You can't put it on without doing that. I'm talking about the top part of the ubr stock, the assembly tube

Got a few pics ?

Not today. The problem isn't major. Gun And stock should function correctly with the small gap. If the problem is bad, then I will upload some

So is there a problem with the receiver or not?

Well I guess not. I was trying to say that the receiver is a little different than it should be.

I have seen UBRs on almost every make of lower and never have I heard of this. I know I have seen atleast 1 DTi with a UBR and there was no gap. The only time I did see a problem with a UBR and a Lower was on a Mega Billet lower.

What is bottoming out on what? Where isnt it fitting in properly. We know you are sdaying a gap...but why is there a gap. The tube should screw in flush if its the tube I think you are refering to.

No not the tube you screw in, the tube that slides over the buffer tube. It doesn't slide all the way in to the lower.