[Zedster]

Just joined the forum, and just picked up my RDB yesterday. This has been a weapon that I have been looking for and just happen to walk into the local shop when they said they received one in.

So I cleaned inspected, and lubed the weapon before ever firing a round through it. After about the first 30 rounds the bolt which were not a constant 30, more like 3-5 at a time just testing it out, the bolt locks to the rear in the full open/eject position and will not release or ride forward. I had to take the weapon apart, remove the bolt/recoil spring assembly, re inserted correctly and it was fine...for about another 20 or so rounds. The bolt release was locked up, I removed the magazine, no debris, casings, etc were in the way, it just was stuck, would not ride forward.

So I had to do this 4 times over the course of about 250 rounds I put through the weapon. When I got home I re-cleaned the weapon, inspected all the parts, and lubed. Only minor normal gun wear was viewed, no damage or obvious reason why the bolt would hang up.

So any other similar experience from anyone? I want to really love this weapon, but I do want something that is going to be reliable. Thanks for any positive input and advice.

 

[HBeretta]

Zedster congrats on finding an RDB. I was just as lucky to walk into my gun store literally 5mins from my house to see one hanging on the wall for sale. Anyway, give us a little more insight. When you say bolt locked up do you mean randomly or when last round fired? Obviously, you have the bolt release on either side or you could use the charging handle to chamber a round on a new mag. My RDB bolt release was stiff out of the box and initially I thought the gun was designed to release the bolt with a loaded magazine only as it was very stiff. Try this...charge the gun while holding the bolt release up to lock the bolt back. Insert a loaded mag and use the bolt release. With mine, after a while the bolt release seemed to loosen up and work while pressing from either side and with or without a magazine empty or loaded inserted. I'll run through some suggestions for you to run with if you'd like. With regard to lubing the gun...not much is needed at all. All I oil is the captive takedown pins and both sides of the bolt carrier assembly along with a light coating on the bolt itself and that's it. Not much oil needed at all. I guess you could oil the hammer spring if you'd like. Also, the universal gas setting for the gun is 3 on the dial. There are 20 clicks on the gas dial. If you didn't tamper with this it should be set to this by default. More importantly, check your casings for a slight indentation on the mouth of the casing which is specified in the manual for proper operation. Check this over time as you break the gun in. Also, go ahead and buy the BCM extractor spring upgrade kit for $5 bucks online and install. This will help keep your extractor pin from walking out. I'd also open a service ticket with kel-tec asking for backup extractor pins and firing pins. They've corrected the extractor pins so ask for them to send you a few. I've had no issues with my rifle at all besides a broke firing pin that I broke myself pulling the bolt apart and it went flying against my ceramic floor. I immediately installed the BCM extractor spring upgrade..all of it..the new spring, insert and o-ring. Not sure if it helped as I had no issues prior but did as precaution due to user reports of the extractor pin walking out. I also fine tuned my gas settings to match the ammo I use the most. The gun has ran flawlessly for me with various types of magazines and ammo. Again, your bolt release should loosen up and be sure to try with a loaded mag if it's not releasing for you otherwise. Alternate sides when pressing the bolt release to help break it in. Let us know of your progress. Also, I do clean my bore after every range session no exceptions although the bolt assembly remains pretty damn clean. Again, I feel all the above is preventive maintenance. I've done the same with my ar15 purchase...buying backup firing pins and BCM extractor spring upgrade kits. Good luck!

 

[Zedster]

Thanks for the info on the pins and ejector, will for sure stay ahead of that potential problem and get the parts. The bolt and captured recoil spring were staying all the way back like the weapon was in the bolt hold open position. But it was totally locked back and could not be released with the bolt release mech or ridden forward with a fresh magazine placed in it. It happened both on the last round and with more rounds in the magazine. At first I though the captive spring was locking up, but it is smooth and maintains and releases tension as it should. As far as lube I hit the bolt and extractor itself, small amount on the rod coming out of and going through the recoil spring and that's about it. I have looked to see if anyone else has had this same issue and did not see another mention in forums or on the internet in general. Will keep an updated post on this just in case another person runs into this same issue.

 

[tjfla]

I ran into this issue and the solution for me was to reduce the gas setting until the bolt stopped jamming open. I was shooting green tips. It only seems to happen with higher velocity rounds and a higher gas setting. I think I read in the manual somewhere that setting the gas too high can cause damage and I surmise that this issue is exactly what it was talking about.

 

[Trunkmonkey]

What has happened to mine and a few others sounds like it might be the same problem your having. What is happening is when the bolt travels rearward, the bolt release arms travel upward to stop the bolt, but then slip along side the bolt jamming the bolt. I have to mortar the gun on the ground while kicking the charging handle to free it. Some have bent the bolt release arms inward to make more contact with the bolt. I did this a tiny bit, and it almost cured the problem. Then I was cleaning the rifle and noticed that the screws in the frame holding my bolt hold open arms were loose. I tightened them up but need to test to see if that was the real reason for my issue, and I think it will be. One of my take down pins is now as tight as it was when the rifle was new after tightening those screws. Ultimately, look for wear marks along side the bolt and bolt hold open arms where they would rub if the arms slid along side the bolt to lock it up.

 

[Znutar]

I'm not sure if my problem is quite the same as described here but at my most recent trip to the range firing wolf steel cased .223 ammo from either Troy, USGI steel or Lancer mags the bolt would lock in the back and I would have to manually release using the bolt stop even though there were still rounds in the magazine in each case. Note that this has not appeared to happen with brass ammo (.223 or 5.45) of either 55 or 62 grains. Have not messed with the factory gas settings as of yet. At this point I've fired about 600-700 rounds through the gun total and have cleaned it about 3 times. I tend to keep the lube light and use Ballistol to clean.

 

[tjfla]

Znutar - Try backing off on the gas setting a couple notches. I have found that there is no universal setting that works for all brands of ammo on my RDB. Tul steel case requires gas setting as high as it will go.

Trunkmonkey - Thanks for the input. I will check the screws and bolt release arms. But the problem seems to be solved on my rifle as long as I don't have the gas set too high on certain ammo.

 

[Trunkmonkey]

That does sound like a different problem than the bolt hold arms. I don't shoot steel case in anything but my AK's. I have read that in 223 steel case is underpowered though. I would think the opposite, stuck cases and the bolt not traveling far enough reward to strip a new round would be the problem. Factory gas setting from full gas all the way to the left if you are shouldering the rifle is three clicks to the right. If the bolt is traveling rearward to fast and hard and getting stuck, like others have said try turning the gas one or two clicks right to four or five clicks total from open/left. Only other things that maybe could cause your issue would be the mag's seating to high up, or the recoil spring and rod binding up. Perhaps the bolt carrier binding up in the back.

 

[Znutar]

That does sound like a different problem than the bolt hold arms. I don't shoot steel case in anything but my AK's. I have read that in 223 steel case is underpowered though. I would think the opposite, stuck cases and the bolt not traveling far enough reward to strip a new round would be the problem. Factory gas setting from full gas all the way to the left if you are shouldering the rifle is three clicks to the right. If the bolt is traveling rearward to fast and hard and getting stuck, like others have said try turning the gas one or two clicks right to four or five clicks total from open/left. Only other things that maybe could cause your issue would be the mag's seating to high up, or the recoil spring and rod binding up. Perhaps the bolt carrier binding up in the back.

sure hope it is not an issue with the recoil spring or rod as that would be a headache. Will try the 2 clicks to the right and see how well it runs the steel and brass...will report back but have to wait until it warms up a smidge here in New England

 

[Znutar]

Discovered something interesting right now...so not to forget I went to adjust the setting 2 turns right. Well I got about 1/2 turn and bottomed out. Seems like my adjustment was only one click "left" from the minimum setting. Based on what I've heard "factory" setting is three click "left" from bottomed out so I have set it for that level and will see what happens.

 

[Trunkmonkey]

So it sounds like you had too much gas forcing the carrier too hard to the rear. I'm optimistic that you have solved your problem

 

[IamScotticus]

This is typical of common gas setting confusion with this weapon.
So I will try to help without using "left and right" references.
Look at the diagram on the end of the rail, the arrows. (+)="more gas", (-)= "less gas".
More gas means there is less restriction in the valve and allowing full pressure to engage the piston. Less gas is the opposite, which is the majority of the range (15-0) which is why this is such a great gun for suppressors.
The normal adjustment range for unsuppressed, as stated earlier, is within five clicks from full "+" and the third click from + being the default.
I will say this, you should be able to run full + with no problems, if KT did their job, the top end of the range for normal 5.56 shouldn't damage the gun. If you are having issues, Id send it back, or leave it as is for an emergency adverse condition setting.
I would agree that the RDB is too delicate to take the pounding from an over-gas condition.

 

[Znutar]

Well tried the gas setting adjustments mentioned and pretty much had a miserable day at the range (not completely awful as I got the wife's 6.5 Creedmoor bolt gun dialed and my AK47 as well). Here's the scoop

It started with the bolt locking back and I would have to manually release it to continue firing despite rounds in the magazine (this was described earlier). This was happening with USGI metal, Magpul PMAGS, Troy and Lancer mags. On the KTOG forum it was recommended that I adjust my gas settings (also described above). So today I went to the range and tried that....it was worse. First I got about three round in and click...failure to eject. Then when I cycled it I would get fail to feed or a double feed...really strange. Tried 3 different magazines and either 55 grain .223 (Remington) or 5.56 62 grain green tips (IMI)...just problem after problem and the double feeds looked strange with crimped cases. Stripped it at the range and checked everything I could and didn't find anything obvious. Reassembled and tried again...bang/click/fail to eject (and this was full gas minus either 2 or 3 clicks). Finally it just plain failed and nothing worked. When I got home and stripped it the firing pin had broken and a small bit was lodged in the bolt. Cleared it with a small punch. Any thoughts? Have an email into Kel-tec to see what they say.

 

[Trunkmonkey]

I had to file the bridge between the two u shaped feed ramps on my RDB because it was having failure to feeds causing brass similar to what you just posted. I didn't have to file much at all, and I would do a tiny bit, then test and do more as needed. Perhaps you have a few things going on as I did, although your's are all culminating during firing. My bolt locking to the rear was the bolt hold arms slipping along side the bolt carrier due to loose screws allowing them to shift periodically. I also broke a firing pin around 800 rounds if I recall correctly. That can happen with an AR for that matter. Keltec will ship a new one if you call and ask. One way or the other, Keltec will fix any problems. Hopefullly it's something easy you can figure out. Took me some time, but mine has been running really well after figuring all this out with the help of the forums, and 1200 rounds. I'd use all brass quality ammo to figure stuff out with.

 

[IamScotticus]

your crimped cases are from FTE's.
The spent case comes back, but not far enough to drop.
The bolt goes forward.
The case neck pushes a new boolit out of the magazine and into chamber.
The next boolit pops up and is pushed out by the bolt face and gets stuck between the feed ramp and the first fresh boolit.
The spent FTE goes wherever.

That is what your crimps are from.

My solution to this is open up the gas more and get more rear travel.
If you have done this and still having the problems you may have a piston weld failure.
Send it to KT.

 

[Znutar]

well heard back from Kel-Tec and they want me to send them the gun...let's see how long this takes...and yes those photos look exactly like what I saw inside the gun though the lighting was really bad at the range...thanks for the visuals.

One question though...I have the custom hand guard from Lee Majors...should I remove that before sending it back to Kel-Tec?

 

[Znutar]

decided to pull off the hand guard and put it back into it's "virgin state"...don't want to risk it in shipping if it gets banged around...easy enough to put back on.

 

[st381]

I would send back in factory condition. Don’t want Kel-Tec balking that you voided the warranty because of a handguard change. I don’t think they would but who knows.

 

[Znutar]

I would send back in factory condition. Don’t want Kel-Tec balking that you voided the warranty because of a handguard change. I don’t think they would but who knows.

done and done...dropped it off at UPS today in its' less attractive furniture...lol

 

[IamScotticus]

Yea, dont send accessories to any OEM.
Standard procedure