Those of you that have had the ‘problem’ know that damaged buffer faces are caused by an out-of-spec buffer retainer pin location. And it doesn’t take much! A ‘beat up’ buffer face is mostly cosmetic, but the more serious issue is if the constant pounding on the pin will eventually shear it off its base and end up somewhere around the trigger control group. Maybe even cause a jamb? I suppose it could.
As you can see, it’s a problem. The first thing you should do is take it up with the firearms manufacturer to have them correct their problem. It IS their problem. So here’s what the buffer retainer does. Nothing but hold the buffer and spring slightly compressed in place so it doesn’t ‘spring out’ during the take-down process. That’s it! It’s not supposed to come in contact with the buffer during the firing and cycling process. It’s really there for convenience, to simplify one’s life so to speak. You can actually remove the retainer and retainer spring and the AR will function just fine. Of course, when you forget you’ve removed the pin is when the buffer will fly out on you during your next cleaning. Don’t ask me how I know… lol.
So, I decided it’s time to design an easy fix. An offset pin would be perfect, right? It would allow the buffer to move further forward and contact the bolt carrier properly and get pushed back off the pin upon reassembly. And it works! I whipped up a new buffer retainer in CAD software and had a few produced. Here’s the drawings. Note the ‘shelf’ which I added to keep the retainer from spinning in place. The buffer tube rests on the lowered shelf shown and the retainer can no longer spin in place.
So moving on to the machine shop results. Perfect! I was concerned that such a small part might present lathing/machining issues, but everything measured dead on. Impressive. I received the parts in steel, and then blued them for those that might be interested in buying one. Here are more pics…
This pic shows the effect of a properly functioning retainer. The bolt carrier contacts the buffer and pushes it back when fully assembled. That keeps the buffer from slamming into the pin during cycling.
Offset buffer retainer. Now in stainless steel.
And the retainer installed. Note the shelf, or ledge, contacts the buffer tube itself and prevents the pin from rotating.
The buffer and buffer spring installed. Note this is a new buffer and will be testing the results over time. I’m pretty confident it will function as designed.