My first Colt LE6920 type is technically a 2011 model SP6920 the only difference was the marking "SPORTER M4 CARBINE", got it new in earyly 2011 shown in this pic just out of the factory box with factory preservative lube.
Rollmarks of the 2011 Colt SP6920 note also the Colt Mfg markings.
Same SP6920 just setup as a M4 clone, close enough for me but not an exact clone.
My next is a correct LE6920 marked M4 CARBINE got new in 2012, also rollmarked Colt Defense. Changed stock with B5 Systems BRAVO SOPMOD & rear sight with Troy folding battlesight.
Rollmarkings of the 2012 LE6920, it came with the detachable carry handle, Colt Defense-Rogers Superstoc lightweight stock with friction lock and two 20 rd aluminum Colt mags (cleaning kit and basic black sling).
Hopefully not my last LE6920 a 2016 lower half with a 2019 LE6920-EPR CK upper half (Enhanced Patrol Rifle factory conversion kit 16"), Magpul MOE K2 grip and B5 Systems Enhanced SOPMOD stock, Magpul MBUS PRO BUIS & Vortex CrossFire gen 2 RDS.
2016 LE6920 markings with QR code located next to the selector
I had been taking personal notes on the Colt model LE6920 and here are some highlights changes (not detailed - please correct me if I'm wrong):
1997 (during gun ban LE model only): First released marked "Colt's Law Enforcement Carbine" with detachable carry handle and Colt Fiberlite type 1 gen 3 (first compact synthetic carbine buttstock)
2002: Buttstocks changed to new (current style) M4 waffle type 2 gen 4.
2004: Changed finish anodize color to black/ dark gray.
2005: Full auto M16 BCG was approved by BATFE.
2009: Mid year hammer and trigger pins changed to mil-spec small diameter.
2011: SP6920 Sporter M4 Carbine was released but dropped end of same year.
2012: M4 Carbine rollmarks released with detachable carry handle and new Colt Defense-Rogers SuperStoc lightweight with friction lock stocks.
2013: 2013 Configuration without detachable carry handle replaced with Magpul MBUS2 synthetic folding sight, no side barrel sling mount replaced sling mounted on bottom of FSB, M4 type buttstock, no two 20rd aluminum mags replaced with PMAG, no more cleaning kit & sling.
2016: LE6920 OEM-1 & OEM-1 stripped models without furniture
2019: LE6920 Trooper, EPR Enhanced Patrol Rifle, M4A1 SOCOM (& Gov't Property marked) etc.
There are different variants like Magpul, camo versions, colors, SOCOM, Mexican, etc.