Structo wrote:Thanks Tonemerc,
I know the pin floats but since it is so light in mass it moves faster than a steel pin.
And if I remember the steel pins will pit the pin tip after a lot of use and especially if it gets real hot.
Since the pin floats, the lock time ( measured in milliseconds) is never consistent in an AR. In theory, if ten shoots are fired, the pin could start forward from a different point at each shot. The only thing that would be consistent would be the maximum firing pin protrusion.
Yeah but in an AR "light in mass" creates two negative issues; first because the pin is lighter it doesn't strike the primer with the same force. The bolt gun setups include an extra power firing pin spring which essentially slams the pin forward harder to compensate for the lighter mass of the pin. An AR doesn't have an firing pin spring to do the same. Any true 5.56 or 7.62 NATO ammo will have harder primer cups. Thus, the low mass firing pin with hard primer cups is not an ideal situation for reliability.
Secondly, low mass means less likely stay in place. So if the very lightweight floating pin starts to move forward slightly before the bolt is fully locked up in the barrel extension and the round goes off, it leaves the alum receiver and ejection port door to take 60kpsi instead of the barrel extension and the barrel chamber.
As far as the stainless steel AR pin pitting from gas cutting or getting hot, a result from automatic fire over a period of thousands of rounds, this just doesn't apply to casual plinking or target shooting. In reality, the item most prone to heat damage is the gas tube.
The point I'm to make is that with an AR you can piss away good money and gain no tangible advantage and in some cases even makes things worse.
TM
