Hello all, Thank you for your time.

I am interested in any information on buffer travel distance(s), preferably Colt Standard Mil Spec Issue , but any type 15/16 info would be useful.

I have come up with my own rough layman numbers from my own machine but would greatly appreciate any educated or experienced info, measurements or guess-tamates from anyone. Please weigh in if you have an opinion.

I understand the variables of different configurations (weight, length, spring, carrier, ect.) can produce varied results, but I need a benchmark or baseline data.

Also, I was wondering about the dynamics of the buffer travel in relation to the carrier, “ideally” is the buffer suppose to stay in contact with the carrier as the weapon is cycled ?

Or is “slap” between the buffer and carrier group a design expectation, or just a symptom of a worn spring/part ?

Thanks again.

I don't have any measurements, but buffers usually strike the rear of the buffer tube -- hence the little rubber bumper on the back of the buffer itself.

It's my impression (again, no scientific measurements here) that the buffer is expected to bottom out at the rear of the buffer tube.  Whether this happens quickly or slowly depends on the gas pressure generated by the round being fired and the mass of rearward-traveling parts (and a number of other variables).

The big deal is that you can expect the bolt carrier to go all the way back, clearing the rear of the magazine by a significant distance, which allows the top round to pop up high enough for the bolt to strip it into the chamber on the forward stroke.  In a rifle or midlength gas system, this is pretty much guaranteed to happen in such a way that the top round in the magazine has reached the feedlips before the bolt has a chance to touch the base of the case.  That is not guaranteed in a carbine-length gas system, particularly when such a system is coupled with a short barrel.