Sounds like a 6920. I have a 6520 like the fellow above. It's worth a good $1,000 in decent shape. The 6920 however is worth a good $200-$300 more new. Prices vary. When availability is good, they can go down as low as $1,250-$1,350. When availability is poor, they can usually hit $1,475 on up to about $1,600. Way back when the AWB expired, some were paying as much as $1,700-$1,800. That's insane.
Key difference is that it has a flattop, F-height sight, detachable carry handle, dual-heat shield oval M4 handgards, and side sling mount.
It's basically THE closest civilian equivalent to the actual military M4 rifle. Nothing comes closer that I know of. So aside from the flattop/handguards/carry handle .which adds cost, it carries a premium for the prestige of being the closest. I know, sounds silly, but it does. It's high demand in law enforcement is what keeps civilian availability relatively low. It's almost seasonal. Sometimes a local dealer down here has 10 of them in shop ...other times they go months without being able to get even one.
