New RDB Bolt Side by Side Comparison

Discussion in 'RDB Bullpup Rifle' started by Lefty2Guns, Mar 3, 2017.

  1. Lefty2Guns

    Lefty2Guns Active Member

    138
    Aug 26, 2016
    Got my new bolt in today. Only took 3 days and free?! Once again impressed with Kel-Tec customer service.

    [​IMG]
    New RDB bolt on the right.
    [​IMG]
    New RDB extractor on the bottom.

    Notable differences:

    • Different shape to the openings of the 'extractor axis pin' and 'ejector pin' on the bolt body.
    • There is a small recess or shelf inside the 'extractor axis pin' hole on the extractor itself (see second photo, bottom extractor).
    • There appears to be a different finish on the new bolt, extractor and even possibly the new pin. The pin itself is black like the rest (old was silver) and feels less slick compared to the old pin (possibly providing more friction).
    • The diameter of the new 'extractor axis pin' is slightly smaller than the 'larger pin' originally intended to fix the pin walking issue (new pin 0.1015in vs old 'large pin' 0.1025in) NOTE: As an experiment I could not get the old 'larger' diameter pin to install fully into the new bolt.

    Did a simple "single finger push test," placing my extended index finger against the back of the punch placed against the axis pin, comparing the tension of my old axis pin (with larger pin and BCM upgraded extractor spring) and the new axis pin as delivered.

    While my old bolt's pin will walk after a fair amount of "single finger pushing," I was not able to get the new pin to walk at all using the same method. Completely non-scientific but I was impressed regardless as I felt I was applying a fair amount of force even if it was only my index finger.

    Can't wait to shoot it!
     
    Last edited: Mar 4, 2017
  2. MarkB1

    MarkB1 Active Member

    277
    Oct 3, 2015
    Are you considering the AR spring upgrade? May not be needed?
     

  3. HBeretta

    HBeretta Active Member

    151
    Oct 26, 2016
    according to gifter it's not and actually caused him some problems i believe. it looks like lefty and i received new bolts today...funny sh!t! lefty...i posted basically same as you in the other thread.
     
  4. butcho

    butcho New Member

    7
    Feb 26, 2017
    Lefty, I sent mine to Keltec yesterday. I hope they will upgrade bolt while they have it? Mine would fire first shot then would put new bullet in chamber but had a dead trigger then when you ejected it and put in another new bullet by cocking then it would fire one then back to dead trigger. Will see what they find. but I am in hopes they upgrade bolt?
     
    Last edited: Mar 4, 2017
  5. Grifter

    Grifter Member

    54
    Feb 17, 2017

    As HBeretta mentioned, my RDB (which came with the "new style" bolt) would not run with the full BCM upgrade installed. The extractor would not actuate so the spent case would be stuck to the bolt (kind of crazy considering there are TWO ejectors on the RDB bolt).

    However, I did find that installing just the larger extractor spring and not the rubber O-ring from the BCM kit worked fine, though there was no measurable improvement over the factory spring on the "new style" bolt.
     
  6. Lefty2Guns

    Lefty2Guns Active Member

    138
    Aug 26, 2016
    I sent my bolt carrier to them when I first got my rifle (they missed an important weld... so a QC issue basically) and they seemed to replace the extractor axis pin at the time without my asking or having had any walking issues, so they may replace your bolt while your rifle is in for service.

    That said, I would absolutely mention to them that you would like them to replace the bolt (assuming it had the old style). Depending on your production date/serial number you may have already had the new one in there.
     
  7. butcho

    butcho New Member

    7
    Feb 26, 2017
    I don't know my production date but I do know my serial number. do you know the serial # that they started at with new bolt? When I get it back I will check to see if pin is silver or black as you said and if not I will call them to get one. I am kind of thinking that my issue had something to do with bolt because once I cocked it and put new bullet in chamber it fired first bullet fine and even put new bullet into chamber, then it went to dead trigger. In other words when I pulled trigger nothing happened. When I would cock it then it would fire first bullet.
     
  8. Lefty2Guns

    Lefty2Guns Active Member

    138
    Aug 26, 2016
    Unfortunately I don't know when they switched to the new bolt, but if you got your rifle recently and it has a higher serial number (check the serial number thread to get an idea) you likely have the new bolt already. Grifter is the only one to have reported his serial (Z0L85) and the existence of the new bolt so far, so that is all we have to go on at this point.

    More importantly than the pin make sure the exterior of the bolt looks like the one on the right in my original post (specifically the differences around where the pins are inserted).
     
  9. butcho

    butcho New Member

    7
    Feb 26, 2017
    OK Again thanks I will check it out when I get mine back. I just hope this takes care of my problems with rifle. My wife and I both enjoy shooting it. This is my 3rd Keltec firearm and this is only problem I have had with Keltec. They give super good service in my opinion.
     
    Last edited: Mar 4, 2017
  10. Lefty2Guns

    Lefty2Guns Active Member

    138
    Aug 26, 2016
    Since you were in the higher "letter" serials you have a better chance. Mine is an earlier Z06** serial.

    Hopefully more people will check their bolts and report their serial number so we can get a better idea of when the switch happened!
     
  11. butcho

    butcho New Member

    7
    Feb 26, 2017
    I did put an acog on it with a red dot and that helped it be more fun to shoot.
     
  12. HBeretta

    HBeretta Active Member

    151
    Oct 26, 2016
    yeah i left the new bolt alone and installed it. i have several bcm kits if ever needed and running with your recommendation and insight to this...figured it best to just install stock and go.
     
  13. scstrain

    scstrain Member

    32
    Oct 23, 2014
    Erica responded to my ticket about a bolt swap very fast. I asked her if I could just easily swap the new for the old without head space issues. She said she would talk to the gunsmiths and get back with me. They told her there could be issues, so she sent me a label to send rifle back so they could do it. They did want to know the serial # of my rifle. I purchased it back in October.

    Erica really stays on top of things. Kel tec should be happy they have her.
     
  14. scstrain

    scstrain Member

    32
    Oct 23, 2014
    Received RDB back yesterday. Not counting shipping time, they had it for about 3 weeks. They told me it could take 4 -6 weeks so they turned it around faster then I expected. They put the new bolt in, polished my feed ramps and re-oiled the rifle. I wonder what oil/lubricant they use, it smells good. Very happy with Kel Tec.
     
    850sub and iamscottasus like this.
  15. SnapShot

    SnapShot Member

    3
    Jul 9, 2017
    My RDB serial number Z0Yxx has the "new" bolt as pictured. The extractor axis pin went MIA on me after about 60 rounds. It appears that this issue still persists. KT sent me a new pin. I'm installing a BCM upgrade spring and plug with it. I hope it solves the issue. Anyone reporting any unintended side effects with the BCM upgrade kit installed?
     
    AndrewK likes this.
  16. Lefty2Guns

    Lefty2Guns Active Member

    138
    Aug 26, 2016
    Interesting, it has been a while since anyone has reported this issue here. I take that to mean the situation has at least improved with the new bolt. Pitty it's still a possibility though.

    I never experienced the axis pin issue but had upgraded my original bolt with a BCM kit just in case and it definitely was an improvement as far as tension on the axis pin that I could feel. No unintended side effects that I can think of.

    edit: a word
     
    Last edited: Aug 13, 2017
  17. bbqncigars

    bbqncigars Member

    26
    Dec 30, 2016
    Went the BLM route myself, lacking the o-ring. No problems so far.
     
  18. AndrewK

    AndrewK Member

    35
    Feb 8, 2017
    Phoenix
    Did customer service send you the BCM kit to avoid the problem? I'm thinking I should get it too.
     
  19. AndrewK

    AndrewK Member

    35
    Feb 8, 2017
    Phoenix
    Man - that is bad news and sorry you ran into this! I thought the issue was completely resolved with the new design. Were there ever any specifics noted about ones that had the problem? Up until your post, I thought it was old design. Did you speak to customer service and were they able to explain why it happened with the new design?
     
  20. SnapShot

    SnapShot Member

    3
    Jul 9, 2017
    I spoke to KT customer service by phone. The guy I talked to denied the existence of a "new" RDB bolt design. Obviously, we in this thread obviously know different. He also talked as if KT was unaware of any issues with the RDB.

    Short of having me send the rifle in, he was unwilling to do anything other than send me a new axis pin. I asked him to please send me a new pin. After a week passed, I was skeptical that a new pin was on its way. I called in again to check the status and spoke with another guy. He was less helpful and asked who I talked to before because KT does not mail out parts. I asked if I could buy a new bolt. He said KT is not selling parts yet since the RDB is still a "newer" design. He did email me asking for a few particulars in order to send me a prepaid shipping label to return the rifle for service. I have not decided to exercise that option yet as the promised axis pin (1) did arrive a couple days later.

    I asked him about the BCM upgrade kit. He said KT does not sanction it. I could not tell if he was actually aware of it or not. I installed the new axis pin and BCM kit complete with the O ring, and I have run a couple mags through it without the pin walking out. I did shoot the rifle oriented such that the axis pin could drop with the aid of gravity. It's staying put for now. It still does not take much force with a punch to push the pin out--much less compared to my AR15 bolt's extractor pin. Maybe my new design RDB bolt is simply defective?