Wouldn't fit initially, now it falls out on it's own - KNS Precision PERMA Firing Pin Retaining Pin

Not a very good product. Maybe it would have been smarter if they had just used a threaded bolt with a conical nut, but whatever the reason, this was near impossible to initially get into the bolt carrier, and now it falls out when the BCG is but tipped on its side. I guess that's fine when it's inside the receiver, but as soon as you take it out, it's easily lost. The reusability concept is nice, but if you lose it, it doesn't matter how reusable it is.