Well. I picked up my RDB last night (I really got tired of waiting on the DT MRD so I traded one of my firearms with a member for his unfired RDB) and here are my first, non live fire impressions on the system.

I went into the RDB openly without prejudging it by its manufacturer (due to my research that their quality has increased due to recent ISO cert). My gun was made on 3/17/17 so it is fresh out of FL.

10,000ft overview:

First of all, like many have said...this gun is stupid simple to break down and work on. I agree.

I think there is a huge advantage here for the RDB vs the TAVOR when it comes to cleaning the chamber. I can service all major components without any additional disassembly. Just like an AUG or PS90 or FS2000.

Everything is in the right place. All the selectors, charging handle, bolt release etc is there. It required really no additional training to pick up and be able to manipulate the weapon safely.

The polymer (this was one of my worries as the prototype guns seemed to lack the fit and finish I desired) is a lot thicker and stronger than expected. There were no mold marks that I could see, very good quality. It is as thick as a TAVOR without being as slick. My only minor concern is the front handguard...it has no heat shielding on it but it is VERY thick...so if you are doing multiple mag dumps, I wonder how well it will hold up against the heat as it directly attaches to the gas block via the take down pin (it does have a steel insert for the pin). This "potential" problem will hopefully be a non issue once the MLOK handguards get released.

There is not a whole lot of lube on it from factory. I highly recommend to breaking it down and giving it a good coat of lube. I used Slip2000EWL.

Barrel and Gas Piston:

Mine is the 1:7 twist. Material is 4140, stress relieved with a government/LP profile setup that is nitride finished. Balances REALLY well, especially for being a 17.4" setup. Nitride finish is very good and found no blems. I like that Keltec used a jam nut for the A2 flash hider vs a crush washer. The barrel shoulder on the muzzle end is generous...it should allow proper attachment of any muzzle brake and suppressor. I welcome the extra barrel length with the same overall length as other 16" bullpups.

The gas block is machined from steel. I'll be honest...the machining could have been a little better...but I am glad to see solid steel vs going cheapo MIM.

The gas plug is easily adjusted. The gas plug adjustment stop is staked, so it should not walk out over use.

The gas piston is a three piece design (gas plug, tappet, bolt carrier) similar to that of POF ARs. The gas "tappet" has AR gas rings like an AR bolt with a spring at the back to help soften the return of the long carrier. This design should mitigate heat well and I would say one of the reasons why it shots very flat as the gas gets managed properly. The factory sets up up the gas setting for M193 ammo...3 click out from 1st gas position.

Bolt and Carrier:

This is one long carrier. If your gun every fails beyond repair in a gun fight...you could probably use the carrier as fighting tool . As you probably know the recoil spring is enclosed inside the long carrier rod. I would put a couple of drops of oil on this rod (again from factory there isn't much lube).

The bolt carrier groups disassembles with ease. Made from steel. The tolerances between the bolt, carrier, cam pin and firing pin is proper. There isn't any slop or too much tightness. Parts fit great.

The firing pin is made from steel as well and appears to be nitrided. The firing pin spring is tapered so it only goes on one way...if you do not have to use some force to put the spring back on the firing pin...you have the wrong end.

The bolt it self is very heavy. It is smaller in length than AR bolt but it has more mass. I am not sure what steel they used but it is a solid chunk of metal.

Charging Handle:

Easy to use. No resistance or hang ups. Easy to deploy. Extra long and because of this...it clears optics perfectly without your hand getting all beat up. It is plastic that attaches to a metal point to make it non-reciprocating (think TAVOR)...however it is very easy to replace should it ever need replacing. Plus, it has the HK slap features if you ever want it. I like the fact that there is two ways of holding a bolt open...either by the BHO device on the chassis or the CH.

Trigger:

I do not have a trigger gauge but I have had pretty much all the triggers in ARs so I have fairly good idea on the "feel" and I've had many bullpups (Tavors, PS90, FS2000, AUG)

By far, THE BEST BULLPUP TRIGGER EVER. Honestly, it has a feel of a 4lb AR trigger. If you can imagine an ALG trigger and a Geissele G2S...combined them...you have the RDB trigger. There is no reason to replace this. I wish Keltec would have went with a metal trigger shoe but I think aftermarket will make one...but I am now just nit picking it. In my rifle's trigger there is a slight take up (almost like a 2-stage, wall...break). No grit or harshness...VERY SMOOTH. Keltec finally fixed the biggest issue most bullpups had.

Receiver:

It is a fairly thick steel. I am not sure what steel is used but it is nitride finished. There is not much to write about here. I am glad they used steel instead of aluminum to protect our face.

Butt pad:

It does its job. It provides enough traction and its contoured well enough to be "dynamic" when it comes to moving with the gun unlike the original TAVOR SAR with its very tall setup. I do wish it was a little thicker like the X95.

Magazine Well, Release and BHO/R device:

Magazine well is very TAVOR SAR ish...the whole magazine interface is. Since I've ran TAVORs before, this was a welcomed feature. It took no time to pick it up and run with it doing dry fire exercises. I do believe an aftermarket magwell would speed things up a bit.

Magazine release. Its a piece of steel that as you press in on it...it rides out of the way. Very simple design. Mine does have a rubber sleeve on the end of it to make it more comfortable (which I think earlier guns did not have). I tried to condition an accidental release and I couldn't do it (which is good)...however I do have small/medium hands.

BHO/R...ergonomically they are positioned perfectly. Buttons are large enough and metal. There is a BHO/R button on each side (very awesome).

Spent Case Housing:

Not much to write here either. It is lined with aluminum vs being just plastic. There are no hang ups or anything that I could see that would cause issues with spent cases. The aluminum is smooth. No roughness.

Length of Pull:

I am 5'11 and 205 lbs with normal proportionate length arms. RDB shoulders very naturally and my hands find themselves about 1 inch before the gas block. So there is an extra 3-4" of handguard to extend my hand on (this is good if you have longer arms than me or if your body setup is different. The RDB offers a wide spectrum of ergos that I have not seen in other bullpups. I do not see the need for VFG or AFG. Maybe a handstop for referencing your hold however the RDB puts you in your natural, most comfortable hold every time I've put the rifle in a ready position.

Pistol Grip and Safety Selector:

If you handled a Keltec PF9 before than you will know this grip. The texuring is about right. I do wish it was a little more "rounded" for my hands but that can be cured for me with a hogue slip on rubber sleeve. I do like that there is no A2 nub on the grip. I do wish Keltec would have a grip plug so that you can carry extra battery or firing pin in there.

Safety Selectors: proper position. easy to access. The first 1/16th inch travel is a bit mushy...but after that its smooth and clicks into position positively. The 30* short throw is awesome. When firing...the selector is out of the way. You can also rest your thumb on it when its in fire (kind of like a 1911). I like that it is ambi as well.


Final Words

I am hoping to have some live fire within a week or so. My initial impression of the RDB is very solid. I did not find any major red flags on the rifle. The ergos and the trigger really steals the show on this rifle. Having slightly longer barrel than a TAVOR with the same compact packaging is welcomed. The piston design seems simple and the bolt is a hefty pig. I think Keltec did a great job with this design. If it functions well (which many have proven it does) than we really have a great bullpup at our hands that is going to be accessible to many (as long as Keltec produces them...I think mine is like 3500th made so far).

Welcome to the club! I love mine. Enjoy it.

Congratd.

I like mine.   I just have a nagging concern every time I shoot it that something will fall off 

Why? From my initial observation...everything is built properly. I guess time will tell though.

I like mine also and "For Me" it works good. I too was worried about parts falling off it is a Kel Tec. The flash hider on mine has come off twice and has had to be put back on. The gun shop I bought it as said it won't come off now after the last trip. Well see.  If the hider comes off again. I am done. Its a freaking jam nut counter tightened against the A2 hider. DAMN I know we talk about why can't designers get away from the AR15 design but shit people whats wrong with a damn crush washer and an A2 hider.
I have thought about doing a review when I hit 1000 rounds through the gun if I still have it by then.

Anyhow we will see!!!

Jam nuts have been used on several other platforms with good results (TAVOR is one I can recall)...I've used jam nuts to time a muzzle brake on ARs. Wonder why it came loose on you. However that is an easy fix and wouldn't deter me on this platform (or any other for that matter).

Yup...

Actually, I much prefer a jam-nut to a crush washer.  And, since I replace A2 muzzle devices with good flash suppressors that don't need to be indexed, I even prefer lock washers to crush washers...

Just sayin'...

Forrest

Definitely grabbing one in the next year.. only question is which model, standard, C, or So, and 5.56 or 6.5 Grendel.

I went with the standard model in 5.56