Staking the AR Buffer roll pin for added reliability.

[Ethan Verity]

After putting maximum effort into building a reliable defensive rifle with quality parts, the darn thing still has a malfunction at the range simply because that little roll pin in the buffer started walking out and rubbing on the spring!

I didn't even think of that as a potential problem. Now that it has happened, I have staked the pin on both sides. I used a steel punch, and tapped it a few times close to the roll pin so that some metal would extrude over the pin. Good to go!
Another 1K rounds since then, and the pin has not budged at all. If you're going to potentially bet your life on a tool, you might as well cover all the bases.

 

[sarduy]

I have to admit that this is the first time i hear of one those walking out and causing a malfunction in all the years I’ve been dealing with AR, but if it removes a possible malfunction go right ahead, as for me, i never have and probably never will stake it.

 

[greyling22]

You could probably just leave it out. I like to never got that plastic piece out of the aluminum body when i was gutting one to build a lighter weight buffer.

 

[GunnyUSMC]

This is only the second time I’ve heard of a buffer pin walking out. The first one was on a friend’s rifle, years ago. The problem was that the roll pin was not the correct size. I replaced the pin and the problem was solved.
There are two reasons for a buffer to come out. One is that the roll pin is undersized, or the hole in the buffer is drilled oversized.

 

[mcb]

I have seen a second smaller diameter roll pin put in the first one to lock it in.

 

[Ethan Verity]

Figures with my luck I would experience a super rare malfunction, lol. Oh well... even so, I'll probably continue to stake my AR buffer pins in the future... just in case.

 

[Riomouse911]

At least you figured it out before you put it into action.

Like the others have said, that’s a new one for me as well.

Stay safe.

 

[12Bravo20]

This is only the second time I’ve heard of a buffer pin walking out. The first one was on a friend’s rifle, years ago. The problem was that the roll pin was not the correct size. I replaced the pin and the problem was solved.
There are two reasons for a buffer to come out. One is that the roll pin is undersized, or the hole in the buffer is drilled oversized.

There has to be a reason for the pin walking out as Gunny stated.

I have never seen this happen in all the years of shooting and working on M16 rifles in the military and AR15 rifles as a civilian. Now I can see this happening from someone constantly taking a bugger apart and/or using the wrong tools for the job.

 

[Ethan Verity]

Now I can see this happening from someone constantly taking a bugger apart and/or using the wrong tools for the job.

It was a band new buffer, purchased directly from a reputable parts distributor (Armalite). It went straight from the package, to the rifle, never disassembled or fussed with in any way.

 

[12Bravo20]

It was a band new buffer, purchased directly from a reputable parts distributor (Armalite). It went straight from the package, to the rifle, never disassembled or fussed with in any way.

I never said that you did take yours apart or try to accuse you of doing so. I mentioned that is the only time I can see one being bad.

And if yours was bad straight out of the package then it is a quality control issue with who ever made it.

 

[GNP]

There has to be a reason for the pin walking out as Gunny stated.

I have never seen this happen in all the years of shooting and working on M16 rifles in the military and AR15 rifles as a civilian. Now I can see this happening from someone constantly taking a bugger apart and/or using the wrong tools for the job.

I could see it happening if the hole was drilled slightly too large....I have seen that before, though not in a firearm.

 

[12Bravo20]

I could see it happening if the hole was drilled slightly too large....I have seen that before, though not in a firearm.

I have seen it when a dull worn out bit is used or the machine operator didn't properly set his machine up and the tooling has excess runout. It happens from time to time.