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Barbarossa
06-02-2009, 9:03 AM
So I figured out why people stake or locktite their castle nuts. :kest:

I had two double feeds followed by misfires at the range. I ended up having a live round stuck in the chamber that wouldn't extract.

Then out pops the buffer retaining pin when I break the rifle down. Seems my buffer tube worked itself out just enough to allow it to come free, and cause problems.

I also had to hunt on the ground for my take down pin detent spring. (fun!)

Sent 80 rounds down range, before I had to pack it up. :61:

Nessal
06-02-2009, 10:21 AM
Tighten that thing down! If you need, I got a car stock wrench.

rkt88edmo
06-02-2009, 11:33 AM
Aren't they supposed to be staked? no loctite necessary.

Nate74
06-02-2009, 11:52 AM
How does the castle nut backing off cause misfires? If the whole buffer tube came off sure, but just being loose, I don't quite follow?

I've never done anything more than just tighten them down... maybe I've been lucky.

DDRH
06-02-2009, 12:02 PM
this a dumb question, but what's a castle nut? gotta pic? it would help a lot. thanks!

Nate74
06-02-2009, 12:31 PM
http://dynamicarmament.com/images/dpmsparts/castlenut.jpg

Used to secure the buffer tube to the lower receiver.

DarkHorse
06-02-2009, 1:20 PM
...on carbine-type buttstocks

Nate74
06-02-2009, 1:37 PM
...on carbine-type buttstocks

Yes, yes. Good point. I forget that some guys go with the "old school" fixed stocks:)

aplinker
06-02-2009, 2:35 PM
The SOPs are there for a reason. If you actually use your rifle you'll likely run into one or two of the standard issues (carrier staking, buttstock staking, loctite on sights, etc).

Just do them right. ;)

Barbarossa
06-02-2009, 2:45 PM
How does the castle nut backing off cause misfires? If the whole buffer tube came off sure, but just being loose, I don't quite follow?

I've never done anything more than just tighten them down... maybe I've been lucky.

It was causing mostly misfeeds, FTF's, & FTE's.

Bolt wasn't cycling forward enough to strike the primer. I was also having extraction issues, as the bolt wasn't engaging the cartridge.

DanHuuN
06-02-2009, 2:56 PM
What I am wondering is how does that happen? I understand that castle nuts can come loose and the stock becomes wiggly and not aligned properly. However, how does the buffer retaining pin pop out? The castle nut coming loose would in no way allow the retaining pin to pop out. On a carbine/collapsible stock the actual buffer tube needs to be turned at least 1/2 - 1 whole turn in order to lock the retaining pin in place or remove it. Maybe I'm wrong but when I visualize what you are talking about I just don't see it happening JUST because of the castle nut coming loose. Correct me if I'm wrong as I am just trying to visualize the issue and NOT trying to be an A**

Barbarossa
06-02-2009, 3:54 PM
Dan,

I agree, the buffer tube should thread in to where the pin is captive. It would be necessary for the stock to rotate, or the pin to slip past the tube.

I assumed that with casual range use, just tightening the castle nut would be fine, but when it became lose, the stock must have twisted enough to free the pin; or some damage happened to some of the parts.

I'll need to dig into it next weekend and see.

DanHuuN
06-02-2009, 3:58 PM
Dan,

I agree, the buffer tube should thread in to where the pin is captive. It would be necessary for the stock to rotate, or the pin to slip past the tube.

I assumed that with casual range use, just tightening the castle nut would be fine, but when it became lose, the stock must have twisted enough to free the pin; or some damage happened to some of the parts.

I'll need to dig into it next weekend and see.

Cool, let us know how it works out for you. Hope all goes well.

IndependentArmamentCo.
06-02-2009, 6:24 PM
DO NOT "Loctite" the castle nut. It should ALWAYS be staked, period. All our builds come with staked castle nuts, no exceptions...and now you know why. :)

cmace22
06-02-2009, 7:21 PM
So I figured out why people stake or locktite their castle nuts. :kest:

I had two double feeds followed by misfires at the range. I ended up having a live round stuck in the chamber that wouldn't extract.

Then out pops the buffer retaining pin when I break the rifle down. Seems my buffer tube worked itself out just enough to allow it to come free, and cause problems.

I also had to hunt on the ground for my take down pin detent spring. (fun!)

Sent 80 rounds down range, before I had to pack it up. :61:


Sooooooo, did you assemble the lower? ;)

A stock with a loose CN is a hard one to miss. They rattle and shake and are very easy to see right away.

So let me see if I got this right. Your castle nut came loose, the stock rotated 90-180 degrees freeing your buffer retaining pin. Because of the rotation of the stock, your buffer spring was elongated causing your FTE's and FTF's. All while your rifle was being fired from your shoulder.

Obviously a Plant
06-02-2009, 8:36 PM
So while we're on the subject, what is the best way to stake a castle nut?

Barbarossa
06-02-2009, 9:16 PM
Yeah I built it myself. My first build. I figured for a bench rest gun, just tightening it would be fine. I found out otherwise. Been a good learning experience.

J_Rock
06-02-2009, 9:24 PM
Well now you know...If you shoot enough s*** will happen, things will break its inevitable.

Stake your castle nut, stake your gas key, if something has screws and cant be staked like iron sights, scope mounts random stuff you bolt down on your gun locktite it down.

JTROKS
06-02-2009, 9:34 PM
Originally Posted by Nate74
How does the castle nut backing off cause misfires? If the whole buffer tube came off sure, but just being loose, I don't quite follow?

I've never done anything more than just tighten them down... maybe I've been lucky.


Posted by original OP:
It was causing mostly misfeeds, FTF's, & FTE's.

Bolt wasn't cycling forward enough to strike the primer. I was also having extraction issues, as the bolt wasn't engaging the cartridge.

On some ARs with M4/CAR type stocks the buffer tybe may not fit very tight and the castle nut keeps it in place and straight. When the castle nut is loose the buffer tube may become loosely fitted thus leading to eratic cyling causing FTE, FTF. With the buffer tube being crooked the bolt will be slamming to the side of the buffer tube instead of traveling straight back. I hope that explains it some.

cmace22
06-02-2009, 10:46 PM
Yeah I built it myself. My first build. I figured for a bench rest gun, just tightening it would be fine. I found out otherwise. Been a good learning experience.


i have had my share too :thumbsup: