I finally got around to putting parts into a Charles Daly Defense lower I had and the Takedown Pin won’t latch in the closed position though it does latch in the open position.
I tried two different pins from different LPKs and both do the same thing.
close inspection reveals that it is not seating fully flush against the receiver. tapping the pin with a plastic hammer to fully seated causes it to bind tightly and needs to be tapped back out.
the LPK is Stag and all other parts work well and look good.
I had a similar issue where I had to use a small brass hammer and punch to engage the take down pins in and out. After a few hundred rounds, it did loosen up to where I can do it by hand now. Hopefully this will be the case with you also.
thanks for the reply but I don’t think this is the same thing.
I’m not attaching the upper yet. I’m just function checking the lower after assembling and the takedown pin won’t engage the detent at all if I slide the pin in normally.
there appears to be a very slight gap between the receiver and the pin seating fully. I’m guessing this gap is .015" and I have to tap it with a plastic hammer to get it to seat flush. after this, it is bound up and I need to tap the pin from the other side to get it to slide out.
again, this is without the upper installed.
it seems like either the pin or the receiver is out of spec though I did try two different pins.
10-4. I will keep track of this thread because I have a Superior Arms lower that was given to me and it has the exact same issue with the front take down.
I recently assembled some lower with Stag LPKs and had the same problem. As I swapped components to isolate the problem, I found it followed the pin.
It appeared that the hole in the takedown pin nearest the flange that the detent engages was either in the wrong position, too shallow, or both. I opened them up a bit and that corrected the problem.
this sounds exactly like my problem except it is following the receiver as the problem repeated with two different pins.
what did you use to open the hole?
I tried to open up the hole in the pin with a very tiny gold-tipped drill bit in a dremel tool but all that accomplished was it polished the pin up a little bit. (those pins are hard…)
I used a very small drill bit. It didn’t take much.
You’re using two different pins, but are they from the same manufacturer? I think you said at least one was a Stag, which is what mine were. If the second is as well, there’s a trend…
The spring being too long wont allow the pins to move freely and it requires a tool to get them out.
You are having the same problem w/ 2 LPKs on the same lower. Does the take down pin move freely in the lower w/o the detent and spring installed?
That should rule out the lower as a problem.
If you have access to a caliper, is the detent channel depth the same on the pin in both positions?
Sometimes when the lower is drilled for the detent spring holes, a tiny bit of material can be left behind making the pins very hard to move w/o trimming the spring a tiny amount.
So thats why I say it sounds like a spring problem.
I see. though I don’t think that is the problem as the detent easily locks the pin when it is fully retracted. and the takedown pin moves freely in the lower without the detent and spring installed.
I do have a digital caliper. I measured the two different pins (and several spare detents) in regard to diameter, length, distance between depressions in the end of the channel for the detent to drop into. they appear to be identical to within .0001". I don’t know what spec is supposed to be, I only know that these two parts were the same.
I don’t know what the problem really is here. based on what you’ve asked me, it doesn’t seem like the spring is the problem. it just seems like the pin is not going deep enough into the receiver to give the detent room to drop into the hole.
I’m going to continue gently tapping the pin fully into the receiver and then back out, hoping this will loosen whatever is binding and preventing the pin from fully seating.
thank you for taking the time to try to help me with this…
Something else just crossed my mind, is there a chance the OD of the take down pin is not the same all the way through?
If it tapered to a slightly larger OD the closer it gets to the stop on the pin, that could give you problems seating the last few 16ths of an inch in the receiver.
So have you tried snipping a little off the spring yet? If the spring is too long or the hole too shallow, it will put enough force on the detent to bind it against the takedown pin, not allowing it to move within the lower properly. The spring is a very cheap part, if that’s why you’re hesitant.
no, I haven’t cut it. and I have other parts so that is not why I’m hesitating. it just seems counter-intuitive to my problem. for the record, I have tried several detents, springs, and two different pins from the same manufacturer, all do the same.
neither the spring nor the detent is binding. the pin moves freely in and out. it works perfectly in the “out/open” position but not the “in/closed” position. as I withdraw the pin, I can observe the detent drop in to the hole/depression in the end of the channel as it clicks into place. this, to me, is not indicative of a spring or detent defect…
also, even with the detent and spring removed, I observe that the takedown pin is not going deep enough into the receiver to seat flush. if I tap the pin flush into the receiver, then it binds and is difficult to retract.
I’m sure this is my problem. I just have to find out why it is not seating all the way. thanks for the reply…
like it’s tapered? no, according to my digital caliper it is the same diameter at both ends.
the only thing I can detect with the pin is that up very close to the cap, there is a ring of material that appears to have been missed with the cutter.
it is so slight that I would miss it with the naked eye but it showed up as a bright ring after tapping the pin flush with the plastic hammer and retracting it several times. there is a corresponding bright area on the receiver as well. I’ll get my jeweler’s loupe out today and let you know what I see…
That isnt right.
Every pin Ive seen has either been completely flush throughout, or has a slight recessed channel at the end like my RRA part does.
Contact Stag and let them know they have a batch of Take down pins that are out of spec.
Is it both pins or just either the front or rear?
well, as the song says, “what a difference a day makes!”. or in this case, two days…
anyway, rather than calling either manufacturer with some non-specific problem, I wanted to wait until I had more information. I decided to just work at gently tapping the pin in and out with the plastic mallet to see if that would improve things. also, to get a second opinion, I put the lower in my range bag and headed over to visit my brother.
as luck would have it, the lower sat in my cold car for about 4 hours and when I went to demonstrate how the pin was not working, it worked just fine! it seated fully and latched in both the full in and out positions and continues to work now that it has warmed back up.
is it possible that contraction from the cold had something to do with the fit?
I don’t know. I just know I’m happy with how it’s working now.
and for the record, the Stag trigger is pretty nice right out of the box…
