Buffer retainer pin wear on one side

[MrBlazito]

Besides misalignment between upper/lower is there any other reason why a bolt carrier would wear one side of the retainer pin? The lower is spike's tactical and the upper is vltor. They seem to align perfectly. The BCG has some wear in the groove where the retainer pin made contact with one side of the groove.

[PyroFox79]

Can't say I've ever seen that. I would figure that it has something to do with the pin hole maybe being off a bit and with the bolt going back its hitting it.

[Lonestargrizzly]

Maybe the spring isn't in there correctly, or it shifted.

[CouchOperator]

Probably an put of spec lower. Seems to be increasingly common on spikes

[armor2111]

Buffer pin hole.

The buffer pin hole is to large or miss aligned. You can ask the manufacturer if they will take care of it or have a smith fill the hole and redrill the hole .

[CouchOperator]

Give us a straight on shot like this

[MrBlazito]

Can it be an out of spec carrier? I don't even remember where I bought it from. It has no logo/brand. I would rather it be an out of spec bolt carrier than the lower.

[CouchOperator]

Your threading looks wayyyyy off to the left. There is visibly more threading cut into the left side than the right. If the buffer tube is threaded in that far to the left, regardless if the buffer retainer hole is centered, the bcg is being forced to one side while cycling, which would put wear on the right side of the buffer retainer.

[MrBlazito]

I'll be contacting spikes tactical with these pics and see what they say.

[Cuda440]

The cam action of the bolt rotating clockwise as it extends under gas pressure will alternately try to rotate the bolt carrier counter clockwise- which could cause rubbing on that particular side of the buffer pin if theres enough clearance and slop between the bolt carrier and upper.

Id check to see if the bolt carrier seems sloppy in the upper, and possibly try a different carrier to see if its any tighter

[MrBlazito]

The bolt carrier is in the upper pretty snug. I swapped out the bcg with another one and can tell no difference as far as how tight it sits in the upper.

[SmallShark]

it looks like the pin just turned. the mark was created by the buffer hitting it

[CouchOperator]

it looks like the pin just turned. the mark was created by the buffer hitting it

It has visible horizontal scratches

[darkwater]

Not sure if it's the angle, but doesn't the buffer retain pin look farther in than the example given? I count 1.5 threads on the OP's between the pin and the edge of the trigger well, vs. less than a thread on CouchOperator's. Plus, the OP's buffer tube seems more recessed vs. CouchOperator's. Does a lateral shift like that make a difference?

[MrBlazito]

Got a reply from spikes tactical.

"Hi,

It’s not uncommon for that pin to get beat up a little bit but it will stop at a certain point because the Buffer ultimately rests against the back of the BCG. Are you meaning the wear is on the side where it rides in the slot on the BCG?"

I guess he misunderstood. I replied and told him that the pin got shaved on one side and the BCG has some wear on one side in the groove as well. Definitely not normal wear. We'll see what the next reply will say.