Beaglepopz Posted June 18, 2020 Report Share Posted June 18, 2020 Mine is the (infamous?) Aero Precision M5E1 DPMS/LR .308. On the compatibility front, this was bought as a complete upper (Ni.B bcg) and lower by AP. 18 " ssb, ported @ .089 , stock gas block. Lower is carbine, stock 2.5" 3.745 oz. H buffer, 7" tube and a very stiff 11" spring. Outta the box it was a single shot, no cycling at all. After all the initial diagnostics; gas port size, block alignment and gas key verification as well as trying 3 types of ammo, 2 types of mags and generously lubricating...still short stroking. I did remove one of the two rubber extractor claw spacers, providing at least some intermittent extraction but no feed. I began looking at the buffer assembly. I started with the spring, I got the springco orange and seemed to make matters a bit worse. It measured 11.25" I was convinced my problem was in the lower. I found an AR10 carbine spring from LUTH-AR measuring 9.75", I paired it with an H3 2.5"(5.3 oz.) buffer. We got cycling! It functions but is it right? I know AR10 specs vary, so I ask...1. is the No Logo Nickel Boron bcg that AP provides longer than the others ? (nitride, etc.) does anyone have an applicable aero bcg they could measure? 2. Some folks are claiming the gas tube on the mid length AR15 is shorter by as much as a .25" compared to the AR10. this could be an issue? How far should the gas tube protrude into the chamber? 3. what are the trouble signs of the wrong buffer/spring combo? In closing, I have not checked head space but I haven't seen any evidence on spent casings to indicate such. Although I am noticing some "flecs" of brass in the bcg chamber that I'm not accustomed to (just un-worn feed ramps?). The simple response is to ship it back for warranty and yes I've been in contact several times w/aero, they'll only take the upper tho. this rifle is 1000% aero built and assembled. this does NO good and cheapens their reputation. Tired of the DPMS/LR platform mantra they spew, I want the knowledge and the right fix not just make it go bang. can you guys help? Quote Link to comment Share on other sites More sharing options...
shooterrex Posted June 18, 2020 Report Share Posted June 18, 2020 Sounds like you got it sorted out. Yes your buffer was too light. The springco orange spring is good to go also. The little brass bits will go away as everything wears in. Quote Link to comment Share on other sites More sharing options...
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