Kel-Tec gives the OAL as 27.3" with its 17.3" barrel. The weight unloaded is 6.7 lbs. The barrel is 1:7" twist. There's a long, T-marked M-1913 Picatinny rail on top but it comes without any sights. I am debating what kind of optic to mount, but it will probably be something along the lines of a 1-4x variable, not just a red dot.
The RDB is a new design, although the bolt itself is very Stoner-ish and it takes AR15 magazines. It came with one 20-round MagPul P-Mag, an owner's manual, and a sling.
There are numerous sling mounting points for the hook-style attachments. In the pic above I had it mounted as a 2-point sling but I later switched it to a single-point using the swivel located in front of the middle takedown pin.
It's a long-stroke, gas piston design. The gas is adjustable to account for variations in ammo or the amount of crud in the gun. However, reviews I've seen state that very little fouling gets into the action. Empties eject out the bottom, through a port behind the magazine well.
The action is very simple and breaks down with only something to drive out the takedown pins. (They may loosen up over time.)
As a southpaw, the best part to me is that it's totally ambidextrous except for the HK MP5-ish charging handle. It can be reversed without tools. All I had to do was field strip the rifle and then put it in the other way when I reassembled. My initial impression of the rifle is that the ergonomics are outstanding.
Because of the long linkage between the trigger and the rest of the firing mechanism, most bullpups have lackluster trigger pulls. Not so in the case of the RDP. It's actually pretty good with some takeup but it's only around 5 pounds.
Between the adjustable gas system, the lack of fouling in the action, and having the ejection port on the bottom of the rifle so gas gets vented downward, it's supposed to be an awesome suppressor host.
In typical Kel-Tec fashion, they are scarce as hen's teeth, though. Kel-Tec announced it a few years ago but they just started shipping in 2016. They are still really hard to find in shops although there are a bunch on Gunbroker.
MAC posted a nice, in-depth review of a pre-production sample on YouTube in 2015:
I should be able to take it out in the next week or two and will post a follow up after I am able to shoot it.