We have heard of three separate cases where our lever had dinged the selector stop on customers' receivers. The selector stop is something that is, in my opinion, superfluous, the detent hole and detent do their jobs just fine without it. Since most receivers have them (the only ones i know of that do not are Colt, and Armalite AR10), if the selector lever comes in contact with the selector stop, the selector stop is doing its redundant duty by preventing the lever from being rotated past where it should be stopped.

On the other hand, when the lever comes in contact with the selector stop, it doesn't necessarily mean the lever would have over traveled had the selector stop not been there. Forged receiver dimensions can be all over the place even from the same manufacturer. If the selector stop's bottom is not milled tall enough, it could come in contact with the lever every time the selector is switched to Safe slightly before the detent is fully engaged.

Furthermore, our detent holes are 0.005 larger than the detent itself. Made any smaller, there would be very little tolerance for debris. The slack must be there for the detent to fall inside the detent hole with some room to spare, and this translates to a tiny bit of play in rotation when the detent is engaged. The play is much smaller than a factory selector, but by necessity, it is there.

Our levers, being serrated, have angled ridges almost all around. When they come in contact with the selector stop, the contact area is smaller and the effect is more pronounced as the force is concentrated on a few ridges. Factory selector levers top and bottom are smooth and have a greater contact area, so they will ding the selector stops with less effect on finishes.

This is purely cosmetic, as even if the selector stops weren't there, the detent and detent holes will handle their jobs as designed.

I suspect most users either have not noticed, or they have seen it but figure it's normal. The marks come from two ridges of the serrations making contact with the selector stop.

On a factory selector lever, since it's flat, there's greater surface area making contact with the selector stop so the wear/marring is even.

One thing we could do is to mill a flat on the top and bottom of the levers to create a flat surface where it's expect to swap paint with the selector stop. This will add to the cost of the product, while functionality wise, it doesn't add anything to it. For those that don't care, the extra cost doesn't benefit them.

When we have, in the past, modified or added things to the kit (e.g. inclusion of the KNS detent, widening the selector center flat area to be more compatible with Geissele triggers), there had never been a price increase. So for those that don't benefit from these improvements, they're no worse off since it didn't cost them anything.

Milling two extra flats on each lever will add to the cost, while bringing no improvement to the levers, its only purpose is to avoid marring the selector stop. While we haven't completely ruled out the possibility, at this point we can't justify the cost...