Got a new KAC SR-15 IWS lower today at a LGS…and has some noticeable differences from my QD cup lowers for example. I’m wondering if maybe we can get a database going of SR15 lower specs that correspond to serial and estimated date of manufacture.
KM802XXX: Bought from Lawmen’s June, 2010. QD cup lower receiver. Non silver finish 2 stage match trigger (no KAC on side of trigger). Small ridged left side mag release. SR15 marked buffer. KAC ambi safety non scalloped. Black finished RE unstaked. LMT marked SOPMOD stock. Slight movement in stock to RE fitment. There is a step right before the flare of the magwell. Appears to have a Colt OEM style mag release.
KM900XXX: Bought from Lawmen’s December, 2010. QD cup lower receiver. Non silver finish 2 stage match trigger (no KAC on side of trigger). Small ridged left side mag release. SR15 marked buffer. KAC ambi safety non scalloped. Black finished RE unstaked. LMT marked SOPMOD stock. Slight movement in stock to RE fitment. No step right before the flare of the magwell. Appears to have a Colt OEM style mag release.
KM909XXX: Bought used from gun show December, 2018. End Plate Sling Mount Non Rotational P/N:22051-1. Non silver finish 2 stage match trigger (KAC on the side). Small ridged left side mag release. SR15 marked buffer. KAC ambi safety scalloped. LMT RE with dry film lube Grey finish & unique design to capture buffer retaining pin, unstaked. LMT marked SOPMOD stock (has a more course texture than the last two). Absolutely zero play in the stock. I’ve never felt a better stock/RE fit in my life, truly hydraulic to the naked touch. Much smoother mag release than the previous two in terms of texture. No step right before the flare of the magwell
*** The KM909 lower with KAC marked trigger blade, yet no new silver finish has a perfect 2 stage trigger in it in every way possible. Zero creep. Short take up into a firm wall, and I’d say it breaks more like an icicle, than a carrot if I may steal Mr. Geissele’s phrase. The two lowers from 2010 had great KAC triggers, and were very much equal to the Geissele SSA trigger. This trigger is much more along the lines of the SSA-E. Overall minus the collectability value given it doesn’t have QD cups, this lower receiver is significantly nicer in the refinement category over the first two from 2010. The trigger and Stock/RE are very much noticeable differences, and the scalloped lever is nice as well. The new end plate ambi sling mount is much more useful as well.
My purpose for starting this thread outside of potentially getting a nice little serial database for SR15 lower configurations, is to find out from other fellow SR15 IWS owners when the KM909XXX lower might have been made, or purchased?
It doesn’t seem like the latest specs without silver finished trigger, and it has a small ridged ambi mag release vs. wavy or large ridged ones I’ve seen recently.