Anderson AR lower, what to do next time

[rugerla1]

I'm sure there's an easier way to fix/diagnose what I ran into last night. I figure many of you have ran into it, just curious what y'all do. 

I had a CMMG LPK without the FCG and decided I'd go ahead and put in the pivot pin, bolt catch, and mag release until my LBK comes in. Figured it to be a 5 minute job like usual, but not so much. Mag release and bolt catch went in easily, pivot pin wouldn't slide in. I grabbed my little hammer and tapped it a little bit, then tapped it back out with a punch thinking it may have just been stubborn. 2 hours later of thinking, tapping in and out, using a dremel with soft pad to smooth out the pin and it would go in but still extremely tight (too tight to do by hand). I got home from the woods today and tapped it in and out probably 50 times and I think it will work now, I'd rather have it a little tight than too loose. I'm assuming the holes were out of spec since the pin will fit into my Matrix lower just fine. BUT I smoothed the pin out last night, so that's just an assumption as of now. I didn't really feel comfortable running a drill bit through the holes, figured I'd mess up more than I fixed.

Anyway, thoughts, comments?

[gregintenn]

Two things you could do......make the pin smaller, or the hole bigger. Emory cloth, a bit of patience, and a lot of checking fit should work. A tight fit is a better situation than a loose fit.

[rugerla1]

Two things you could do......make the pin smaller, or the hole bigger. Emory cloth, a bit of patience, and a lot of checking fit should work. A tight fit is a better situation than a loose fit.

Thanks Greg, I was looking all around the garage for something that would do it evenly. Last thing I wanted to do was make one hole bigger than the other. I also was worried about making the pin too small and it not fitting the upper correctly. I would rather have made the holes bigger to fit the pin, but if the pin was too big for the holes in the lower I figured it would be too big for the upper as well. Hopefully all is well and I agree, too tight versus too loose.

[Garufa]

Often some lubrication helps coax a large pin into a tight hole.

[rugerla1]

Often some lubrication helps coax a large pin into a tight hole.

I was using Rem Oil as soon as I realized it was going to take work. There was no moving it by hand at all, took a hammer and punch the whole way in and out for the first 20-30 times. After that it was getting where I could move it part of the way by hand, then finally today I got it to where I could do it with my hand all the way, though still very snug. But as long as it works with my upper correctly, I'm fine with that.

I didn't know if there was a tip someone might now (sandpaper sleeve, file, etc) for the holes. May not be, maybe just have to do like I did and that's fine too because I was definitely honing my patience skills the whole time :)

[Dolomite_supafly]

ALWAYS modify the cheapest part, in this case the pin.

[rugerla1]

ALWAYS modify the cheapest part, in this case the pin.

Thank you Dolomite, glad that's all I was able to do. I also figured I could replace it whenever my LBK gets here.

[rugerla1]

Just thought I'd give an update. My LBK came in today, finished the lower and test fitted it on one of my completed uppers. Fits great, still tough to push out but is easy enough to engage and with use I'm sure will get easier as they all do. Everything else went together nicely, would buy another Anderson lower even though the other night I swore I wouldn't lol. Finished half the Matrix Aerospace lower tonight and ran out of parts in my spare parts bin. Thanks for all the responses y'all.

[Dolomite_supafly]

Just thought I'd give an update. My LBK came in today, finished the lower and test fitted it on one of my completed uppers. Fits great, still tough to push out but is easy enough to engage and with use I'm sure will get easier as they all do. Everything else went together nicely, would buy another Anderson lower even though the other night I swore I wouldn't lol. Finished half the Matrix Aerospace lower tonight and ran out of parts in my spare parts bin. Thanks for all the responses y'all.

Have you oiled/greased the pin? That can go a lot way in making things work more smoothly, especially with dry anodizing.

[Smith]

They aren't our of spec per say. Anderson uses a special anti friction coating and it is a bit thicker than standard anodizing. You may even find that the upper is rather fitting especially the rear tab. Once you wear down the coating in those areas it'll fit more like normal. Kinda like it starting tight as posed to loose. Edited October 23, 2014 by Smith

[rugerla1]

Have you oiled/greased the pin? That can go a lot way in making things work more smoothly, especially with dry anodizing.

I don't remember putting oil on it when I first tried to install the pin. Probably contributed to some of the stubbornness. But once I'd had it all the way in and out via hammer and punch a couple of times I thought of the fact it may be too dry and kept it soaked from that point forward. Putting it in dry may have roughed the coating up and made it harder than it had to be. But it seems fine now, but I will never forget to make sure it's lubed again.

[KKing]

Kinda like it starting tight as posed to loose.

This. Always this ;).