Different AR-15 problem

[loudshirt]

So I have AR-15 that is having some butt stock issues. First a little back ground. The AR has been sitting in a safe for about 10yrs. I took it out cleaned and lubed it. So while attempting a function check after I reassembled it the bolt kept getting stuck about half way back. If you slightly lift the stock the bolt flies home. So here is the fun part I finally after some work I got the stock off to try and screw it on straight. Well after many attempts I can not get the stock tight again, I have an "extra" spring that I am not sure where it goes or if it is part of the AR. It kind of looks like a spring from an ink pen with one end bent. Now the buffer retaining pin (not sure if that is the proper term, but the part that hold the buffer/spring in the stock) is not seating all the way down. Also the rear take down pin comes all the way out and I am not sure why. So any and all advice would help.

 

[technetium-99m]

There is a detent and spring held into the lower by the butstock, or the small plate (can't think of it's name) that's held in place by the castle nut. This detent rides in the slot in the rear takedown pin and prevents it from sliding freely. It probably dropped out when you took off the butstock. You should have the buffer retainer and spring as well, which tend to be launched out upon buffer tube removal. Depending on the pen, either spring could be your "extra" but I think it's the one holding the detent against the rear takedown pin (note that pen and pin are different here, just trying to be difficult).

There are videos on youtube and arfcom about assembling lowers, give one a watch and you'll see how it all goes together.

As far as your problem, check and make sure the spring and buffer slide freely in the tube and that your carrier slides freely in the upper. It's got to be catching on something if it will only move 1/2 of the way to the rear.

 

[ez bake]

So I have AR-15 that is having some butt stock issues. First a little back ground. The AR has been sitting in a safe for about 10yrs. I took it out cleaned and lubed it. So while attempting a function check after I reassembled it the bolt kept getting stuck about half way back. If you slightly lift the stock the bolt flies home. So here is the fun part I finally after some work I got the stock off to try and screw it on straight. Well after many attempts I can not get the stock tight again, I have an "extra" spring that I am not sure where it goes or if it is part of the AR. It kind of looks like a spring from an ink pen with one end bent. Now the buffer retaining pin (not sure if that is the proper term, but the part that hold the buffer/spring in the stock) is not seating all the way down. Also the rear take down pin comes all the way out and I am not sure why. So any and all advice would help.

Sounds like the takedown pin spring (and you might be missing the takedown pin detent).

If you lean the rifle forward (with the takedown pin installed) and slap the side (to make sure the detent falls forward if its still in there) can you still pull the takedown pin all the way out?

If so, you might want to start looking for a tiny detent that's laying around (or order a new one cause that's a needle in a haystack problem ).

I don't know what could have caused your original problem unless your stock (I presume its a carbine stock) wasn't screwed in all the way and the buffer retainer was getting into the buffer spring coils.

Here's a breakdown of the parts I'm talking about (I'll let you click the link so as not to make this thread too hard to read - its a big pic):

http://www.recguns.com/Pictures/Images/Xm15Diagram.gif

 

[loudshirt]

Thanks for the link. As far as the original problem, I think the stock is either broken or not screwed in correctly. I am going to see about getting a new stock anyway, but I do believe I need to get a the detent and spring.

 

[TJay74]

There is also a spring that rides in the grip as well, it rides against the safety selector switch and gives the switch its tension.

 

[Bobrob]

A neat trick I have adopted for my own is to tap the detent hole with a 4-40 tap and screw in a 4-40 x .125 ss setscrew.

This will prevent the spring form flying out when you remove the stock, or the stock loosens up.

I had to clip 3 rounds off the spring, and grease the crap out of the plug to avoid dis-simular metal corrosion.

If you didn't know it was in there you would never know it.

regards

 

[Jam Master Jay]

A neat trick I have adopted for my own is to tap the detent hole with a 4-40 tap and screw in a 4-40 x .125 ss setscrew.

This will prevent the spring form flying out when you remove the stock, or the stock loosens up.

I had to clip 3 rounds off the spring, and grease the crap out of the plug to avoid dis-simular metal corrosion.

If you didn't know it was in there you would never know it.

regards

That's a sweet idea. I may have to spread it around.

 

[Engineman1960]

I would first check the buffer spring and buffer and inside the buffer tube for dirt, rust & bug -- you could probably use an old t shirt and your cleaning rod -- a white t shirt or diaper will tell if you have a crud coating in side the tube; Their should also be a hole in the buttstock screw and the rear of the buffer tube -- Tapco has some good instruction with pictures about installing a rear stock.

Good luck