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Kel-Tec RDB

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I picked up a brand new Kel-Tec RDB off gunbroker last week for slightly under MSRP. For those not familiar this is a 5.56/.223 semiauto bullpup with downward ejection like a PS-90, and accepts standard AR-15 magazines. Haven't had a chance to take it to the range yet but I'll get it there this week. It's simple to take apart and easier to clean than an AR-15, but not as easy as the RFB (K-T's other bullpup rifle). I moved the charging handle to the right side as I am a lefty but you can see it in on the left side in the pictures. It lies flush underneath the forward section of the upper rail and swivels out like a G36 for use. When pulled back you can lock it by swiveling it upwards slightly like a MP5.

I attached a Vortex Spitfire 3x to it and encountered my first "issue": there is very little gap between the mounting bracket's nuts and the charging handle when fully pulled back. Specifically, my thumb does not fit and did not appreciate the attempt. I may turn the base backwards which would move the screws to the other side, but I think in practice I will end up using the charging handle with my hand underneath it rather than on top which will eliminate the issue.

IMAG0581.jpgIMAG0582.jpgIMAG0583.jpg

Other observations: While it doesn't have a swivel stud underneath the buttstock for a sling like an AR-15, there are still 7 sling attachment points built in, 2 of which swivel freely. The plastic covering over the rear of the stock duplicates the effect of aftermarket kydex cheek covers common on RFBs and KSGs.
 
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beaker

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Interested in a range report. Subbed. Congrats hope it is a keeper

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sgeary

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Looks great, Kel tec always makes innovative stuff. Mind me asking the street price you paid for it?
 
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I had a chance to get 60 rounds off today before it got too dark. BLUF: I think the gun works fine but 60 rounds isn't much to go by.

Details: I changed the gas setting while cleaning the rifle and didn't reset it back to the way it came from the factory. During the first 20 rounds I had 2 failures to feed, one double feed, and the bolt didn't lock back on empty. After adjusting the gas setting (by 1 click) I had no further malfunctions and the bolt locked back properly on empty. Ammo used was 62gr Prvi Partizan. I can't comment on accuracy because there was an issue with the Vortex Spitfire but since this is about the RDB I'll leave it at that. For the double feed, all I had to do to clear it was lock the bolt back and jostle the rounds a little with my fingers in the mag well and they just fell out.

I may make it to the range this weekend for a longer session, family and weather permitting.
 
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MAC seems to like it. I wouldnt mind a Glock 9mm Sub2000.

Im waiting to see how the desert tech MDR in 308 turns out.

Hows the weight?

Mike

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rkwjunior

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Looks like price on GB is from $1400-1600 range. For $2-300 more I'll take a Steyr or a Tavor before that thing. Keltec makes cool stuff but it has a tendency to be on the chincey side and not battle tested.
 
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Range update. Took it for another whirl yesterday and had no problems. For those curious about weight/balance, it's just slightly heavier than an AR-15 (~1/2 lb depending on setup) balanced just forward of the pistol grip. I didn't really notice any imbalance until inserting 20+ rounds into a mag when the muzzle wanted to climb. The trigger is nice and crisp like I've come to expect from Kel-Tec's bullpups.

Conditions at the range were somewhat windy, 10-15 mph from 10-11 o'clock. The target stand swayed periodically but I don't think that affected shot placement. All of these were shot seated with a sandbag front support. The first two pictures are 5 rounds of Prvi Partizan 62gr:

IMAG0605.jpgIMAG0606.jpg

The next two are, respectively, 25 rounds of Prvi Partizan 62gr and 20 rounds of PMC 55gr shot at a ~1sec cadence:

IMAG0608.jpgIMAG0609.jpg

I wish I had brought my chronometer to check the difference between the PPU and PMC ammo. I suspect the PMC was firing a little faster which would account for the POI shift given wind conditions.

Lessons learned:

1) No more small/grey dots with only a 3x optic.

2) Not really RDB related but you can't easily use a .223 cartridge to adjust height/windage settings on the Vortex Spitfire. Bring a screwdriver.

I'm preparing some 60gr Nosler Partitions to try out after Turkey Day & will provide results in a few weeks.
 

frenchman

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The biggest drawback of a bull pup is that tac reloads are practically impossible (says the guy who served with a FAMAS)
 
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At what distance were these shots taken?

100 yards

RFB and RDB, what's the difference? What's the same?

As has been said, the RFB is a forward-ejecting .308 bullpup that takes metric FAL magazines. I've had an 18" carbine since 2009 and there is also a 24" variant now available.

The RDB is a downward-ejecting .223/5.56 bullpup that takes standard AR-15 magazines.

Both rifles are fully ambidextrous with the exception of the charging handle - you have to disassemble either rifle slightly and move it to the other side. The RFB is faster to change over in this respect. Both have magazine ejection levers directly in front of the mag well. The RFB's is smaller and the RDB has a larger U-shaped piece of metal which wraps around the well. I find the RDB's safety selector easier to operate and the RFB's slide release easier to operate. Both have excellent stock triggers.

I expect to make it to the range in ~2 weeks with some handloads and will update with results then.
 
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100 yards



As has been said, the RFB is a forward-ejecting .308 bullpup that takes metric FAL magazines. I've had an 18" carbine since 2009 and there is also a 24" variant now available.

The RDB is a downward-ejecting .223/5.56 bullpup that takes standard AR-15 magazines.

Both rifles are fully ambidextrous with the exception of the charging handle - you have to disassemble either rifle slightly and move it to the other side. The RFB is faster to change over in this respect. Both have magazine ejection levers directly in front of the mag well. The RFB's is smaller and the RDB has a larger U-shaped piece of metal which wraps around the well. I find the RDB's safety selector easier to operate and the RFB's slide release easier to operate. Both have excellent stock triggers.

I expect to make it to the range in ~2 weeks with some handloads and will update with results then.

Thanks. I wonder why they went with two totally different designs, instead of the same for both calibers. Is one any better than the other? By better, I mean accuracy, reliability, usability.
 
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Thanks. I wonder why they went with two totally different designs, instead of the same for both calibers. Is one any better than the other? By better, I mean accuracy, reliability, usability.

BLUF: Yes. Long answer followed by short answer.

The RFB was going to be KT's flagship rifle (still is but not for long IMO). They were going to make it in a variety of calibers and also have a target version with 32" barrel. A German company actually rebarrels and sells them in Germany in .358 Winchester since 7.62 is a military caliber and banned for civ use there. At some point after the RFB went into production the owner of KT, George Kellgren, dreamt up the RDB design. It's simpler to produce than the RFB. The RFB gas piston and piston housing was redesigned mid-production to make it easier to produce but the RDB is still simpler. The RFB has a 42-point gas adjust and needs to be tuned for each type of cartridge you fire through it. I actually don't know how many adjustment points the RDB has, and while it does need to be tuned I didn't have issues firing 62gr and 55gr bullets from the same gas setting. My RFB would need adjusting between 150 and 165gr bullets for example. I can't speak to powder charge weight because I'd be comparing handloads to factory ammo of unknown quantity so it's possible the RDB is just as finicky and I got lucky with the two types of ammo I fired through it. However, my understanding is KT intentionally made the RDB's gas system more forgiving and that has been my experience so far. I expect they will eventually make the RDB in multiple calibers and when they make a 7.62 version, the RFB will go out of production.

So, to answer your question I would say the RDB is simpler to produce. The other -ility's will remain to be seen since it just went into production. My inclination is to say the RDB will be found more usable and reliable, while sharing the same minute-of-bad-guy accuracy you'd expect in a military-style semiautomatic rifle.
 
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BLUF: Yes. Long answer followed by short answer.

The RFB was going to be KT's flagship rifle (still is but not for long IMO). They were going to make it in a variety of calibers and also have a target version with 32" barrel. A German company actually rebarrels and sells them in Germany in .358 Winchester since 7.62 is a military caliber and banned for civ use there. At some point after the RFB went into production the owner of KT, George Kellgren, dreamt up the RDB design. It's simpler to produce than the RFB. The RFB gas piston and piston housing was redesigned mid-production to make it easier to produce but the RDB is still simpler. The RFB has a 42-point gas adjust and needs to be tuned for each type of cartridge you fire through it. I actually don't know how many adjustment points the RDB has, and while it does need to be tuned I didn't have issues firing 62gr and 55gr bullets from the same gas setting. My RFB would need adjusting between 150 and 165gr bullets for example. I can't speak to powder charge weight because I'd be comparing handloads to factory ammo of unknown quantity so it's possible the RDB is just as finicky and I got lucky with the two types of ammo I fired through it. However, my understanding is KT intentionally made the RDB's gas system more forgiving and that has been my experience so far. I expect they will eventually make the RDB in multiple calibers and when they make a 7.62 version, the RFB will go out of production.

So, to answer your question I would say the RDB is simpler to produce. The other -ility's will remain to be seen since it just went into production. My inclination is to say the RDB will be found more usable and reliable, while sharing the same minute-of-bad-guy accuracy you'd expect in a military-style semiautomatic rifle.

If Kellgren has a failing, it is that he can't leave things alone to get enough production volume of one cool thing before he is already tinkering around with the next. Reminds me of a modern day Browning
 
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Range update

Handload data:

Once-fired ATI brass (I did not sort by weight which I should have done in retrospect for better case volume control)
Remington 6.5 small rifle primers
Nosler Partition 60gn bullets

I used Quickload and the optimum barrel time paper (which you can google up) to select two ideal nodes for the RDB's 17.2" barrel. Thus I had one set of handloads with 23.5 grains of Varget and another with 24.5 grains. Again in retrospect, I suspect the OBT paper was written for free-floated barrels which the RDB is not.

I brought my chrono along and got a fair amount of samples; there was a lot more variation than I'm used to in the 23.5gn loads and somewhat less in the 24.5gn. I measured the powder weight in each cartridge with a GemPro 250 so I'm confident in those measures, and the COALs as well.

Here are the results, with a sample of measured velocities followed by targets in that load. These are all 5-shot groups at 100 yards except for 1x 4-shot group, fired from prone with a front supporting sandbag.

IMAG0632.jpgIMAG0629.jpgIMAG0630.jpgIMAG0631.jpgIMAG0634.jpgIMAG0633.jpg

Make of it what you will. I intend to reattack it once more with more consistent brass but that will probably be a few weeks down the road. I think, at a minimum, because the barrel isn't free floated, that it's prone to vertical stringing when stress is inconsistently placed on the forward handguard. My RFB does the same thing.

Toys of the day:
IMAG0636.jpg
 
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