I recently purchased the PSA 16" CARBINE LENGTH M4 CHF 5.56 NATO 1:7 GEISSELE 13" MK14 M-LOK UPPER. This comes with a 16" FN barrel, carbine length gas tube and a Geissele .750" diameter Super Gas Block that is pinned to the barrel. I will be pairing this with the PSA CUSTOM FATHERS OF FREEDOM 5.56 FULL AUTO PROFILE PHOSPHATE COATED BOLT CARRIER BY MICROBEST.
My expectation is that a carbine buffer will be the right match, but I thought I would ask for advice in case this upper is known to have a tendency toward needing something heavier to run well.
Standard Mil-Spec Buffer/Spring is all thats needed, forget all the fancy bullshit, it’s not neccessary, nor will you notice any difference in performance. 99.9% of all the issues guys have with the AR platform is trying to overthink gas blocks and Buffer combos. Its just not needed and usually causes more trouble than its worth for the guy with minimal understanding of the design.
swapping buffers shouldn’t trip up even someone new to the platform. if it did you might also have problems just generally trying to clean it. easier than adjusting the gas block… people have different preferences, but as for functionality i would go with guitarguys advice and just watch the ejection pattern.