JD Machine 308 Matched Upper Lower Take Down Pin Problem

[Justintoxicated]

The Take down pins from my CMMG parts kit do not fit. They fit the upper fine, but the holes in the lower seem to cause the pin to require being tapped in/out of place with a punch.

Also there is a pre-anodizing bur in the rear takedown pin hole that appears to have been created prior to anodizing. What is the best way to remove it. It looks like something dented/mashed the aluminum a little, or maybe is is from the machine they used to mill it, its really small so probably not a big deal so long as I can get the damn pins in.

Is there an easy way to fix these issues or will I need to drive down to JD Machine a 3 time? That's 2 hours of driving for me.

[G38xOC]

my tm10 with dpms kit and jp upper is same . I have to use the hammer and punch . I dont find it big issue for me for now . I guess if there's malfunction in field , kinda hassle to be looking for tools , but I usually carry small amount of tools so . I'm thinking intime , clearance will open up a bit ?

[BDH]

Get the takedown pins with the knob that allows you to pull them out without a punch.
Bruce

[Justintoxicated]

Get the takedown pins with the knob that allows you to pull them out without a punch.
Bruce

that isn't going to fix the problem, they are in there good.

[Damn True]

Tolerance stacking? You might just need to dress the hole with a reamer. Before doing so though I'd give JD a ring, might be a less aggressive solution.

[ott1]

Dremel + 1/8" sanding band.

[Justintoxicated]

Tolerance stacking? You might just need to dress the hole with a reamer. Before doing so though I'd give JD a ring, might be a less aggressive solution.

They stopped answering phone and emails a while back though Guess I'll have to wait till I get the rest of the parts, and hope things have settled down by then. I was really hoping to not have to remove the anodizing on a $700 matched set though.

[gregr266]

I was going to buy a complete lower of there's but as
I was checking it out the same thing was going on. I could not get the front take down pin out. It was I. There good. Even the ffl couldn't get it out. They said that they would have to send it back to them.

[Calplinker]

Fitting issues

Sounds as if it's a really tight fit, which isn't a bad thing.

I put together an AR a few years ago that had the same thing going on. My advice is to NOT try and ream out the holes. Leave them alone and instead shave down the diameter of a pin using a dremel, sander, or file.

This is what I did and it works perfectly. I buggered up my first attempt and shaved too much off the pin so I tossed it out and got another one. At $5 each, it just seems much smarter to modify the pin than either the upper or lower holes.

[mcisniper]

JD sometime run really tight. Will loosen up over time with some use.

[Agustav]

As others have mentioned, it will loosen up after some use. It's happens from time to time and it's not necessarily a bad thing.

If it really bothers you, just sand down the pin a little at the time till you satisfied with the fit.

[Justintoxicated]

I sanded down the pins a little, and sat with a punch for a couple hours punching the pins in and out of the lower until I could force them in by hand (still need a punch to remove them though).

Only minor damage occurred to the lower for the pivot pin problems I removed the Burr with the back part of a drill bit.

I also had to chase the threads for the pistol grip bolt since the screw would stop feeding about 1/2 way in. That solved that problem.

However I seem to have only been able to screw in the bolt catch pin (allen style pin), about 2/3rds of the way before it rounded out the head on the pin. I did not have a bottom tap this small to chase the threads.... What to do now? Why am I having so many problems with this upper/lower? I build a few TM regular lowers in the past and I didn't even have roll pin punches and I did not have any problems....