Might be good, if you can install it. - KNS Precision Bolt Catch Retaining Pin for the AR15/M16 w/3 C-Clip Retainers

In theory, this seems like a simple design, easily installed. If you don't have the right tools, it aint gonna happen. The pin did fit my Franklin Armory lower, but the clips are so small, making it difficult to install. Three clips come in the package, whether you going to bend one or two, or just plain lose it. My frustration got the best of me and I went back to a roll pin. If you can install it, I don't see it being an easy task to remove it either, to switch bolt releases. I give it a 3 because it seems like a good idea, but I just couldn't get it installed. I didn't check any other brands to see if there would be a fit problem or compare billet to forged lowers.