AR Sponsor
Posted: 8/27/2012 8:52:13 PM EDT
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Hi guys,
I'm right in the middle of a new upper build (it's off to be duracoated as we speak or else i'd have pics up...will post when i get it in) 18 in rifle length barrel on this one and i'm pretty excited about finally having an ar with some capacity to be really nice and accurate. I'd love to see how well i can load some rounds up with the newer high bc bullets like the 75-77 grain hpbt by hornady and sierra...rifle twist is a one in 8...77 may be a little too heavy but we'll see once i get it to the range if it likes it or not. what are your thoughts on heavier carrier groups and buffer springs to increase muzzle velocity just a tad bit more and has anyone used the carrier weights made by david tubb's company? Interesting thought but don't know what that will do for my reliability of cycle for ammo. I think (could be wrong) with less dwell time (rifle length gas on 18" barrel) it's going to be a tad under gassed anyways...once again i may be wrong. my understanding of dwell time is that the flight of the bullet down the barrel past the port allows pressure to build up in the gas tube and ultimately more dwell time equals more pressure to ensure the extraction and ejection of the spent round....less dwell time allows less pressure to build up and thus less violence of extraction (also less recoil impulse) ? am i close on that? so if there is more mass in the carrier and more power in the buffer spring it seems the bolt would stay driven into the lugs just milliseconds longer allowing pressure to build higher before engaging the carrier rearward and also resulting in more pressure out the end of the barrel giving more velocity...this is where i'm uncertain....how does all that work together and would it work together or result in system failure to feed, fire, or extract? i know it's splitting hairs and if i really wanted more velocity for distance i would have gone with a longer barrel to begin with...and i agree. just more of a thought experiment and wanted to get more understanding of how all those factors combined to get the end result of function from the ar system. I'm not going for less recoil as my goal just more velocity and better accuracy but dont' want to sacrifice performance to the degree i can only shoot a single specific load from the system. |
AR Sponsor