Fix for a tight rear take down pin on AR?

[ArmedRPh]

I have a Noveske chainsaw lower with a Noveske N4 upper. The rear takedown pin needs quite a bit of force to close and I can't get it out without using a punch. I have tried a different pin, thinking that perhaps the first was bent, no joy. I have also tried the upper in another lower and the fit was exactly what I was looking for...held tight with only strong finger pressure needed to remove the pin. The easy answer would be to just use the second lower, the problem is I have already submitted the ATF form to SBR the chainsaw lower with that upper.

So, anyone have any ideas on how to "loosen" up the fit a bit. I thought about taking a few passes of a rat tail file through the hole in the upper, but I thought I see what the brain trust on INGO thought first.

 

[Indy Wing Chun]

Could it be that the spring is pushing too hard on the detent? Try checking that would be my guess.

 

[ArmedRPh]

comparing the feel of the pin on both lowers WITHOUT an upper in place, they feel about the same. They seem to require similar amounts of force to get them moving. Would that be the case if the spring was pushing too hard on the detent?

Could it be that the spring is pushing too hard on the detent? Try checking that would be my guess.

 

[HamsterStyle]

I have read about people taking a drill bit the same size as the hole and just turning it by hand in there to loosen it up a bit. Never tried it myself, just read about it.

 

[rockhopper46038]

I have read about people taking a drill bit the same size as the hole and just turning it by hand in there to loosen it up a bit. Never tried it myself, just read about it.

Taking out the pins and buying smaller ones, or chucking the pins up in a drill and sanding them down a bit are probably better options. Reaming the receiver holes would certainly work, but once you cut through the anodizing the hard pins will start to wear on the exposed hole edges pretty quickly. I'd leave the receiver holes alone.

 

[Steven]

Some people pay extra for that tight of a fit !
Often a tight take down pin will loosen up with use,
Other wise, always work with the cheapest part first.

 

[Newbomb92]

Throw some Earl on it.

 

[Colt556]

I would leave it as is and see if it loosens up a bit with use. I'd rather have one a bit tight than a bit loose.

 

[95wrangler]

I had a new bushmaster that were about as tight as yours. I put a few hundred rounds thru it and the loosened up so I could use my fingers to take them out. So short answer: shoot it!

 

[nox]

I had a new bushmaster that were about as tight as yours. I put a few hundred rounds thru it and the loosened up so I could use my fingers to take them out. So short answer: shoot it!

Ditto, same problem/solution with my newest PSA upper.

 

[davedolli]

I have had a couple that were tight like that but after a while of being worked back and forth taking down the rifle, they loosened up some.

Dave

 

[HavokCycle]

+1 all the above, before making judgements on somethin id let it break in first. tolerance stacking, all that.

 

[churchmouse]

If it has the same resistance in both lowers without an upper in place then it is just a tolerance issue with that upper and the lower you are using. Shoot it and let everything get happy. If no joy, consider doing some low material removal clearance work.

 

[GIJEW]

When I got my RRA, the take down pin was so tight that I had to tap it out with a punch, but it loosened up after a while. How long have you had that lower?

 

[SAMSON]

Don't mess with the holes in the recievers. Once you remove material from them it can't be replaced. It will probably wear in after enough use and takedown for maintenance, cleaning and such. If you just have to loosen it up polish the takedown pins a little at a time till you get to the point you're comfortable with. Pins can be cheaply replaced, not so recievers.

Loose= bad
Tight = good(Wink, Wink,Nudge, Nudge)

 

[03A3]

Often when you lube up an AR15 real wet then go put several hundred rounds thru it in short order it will start oozing gray colored oil. The gray is aluminum particles.