New front locking rimfire

Discussion in '.22 Rifle/Rimfire Discussion' started by rfr, Jun 25, 2010.

  1. rfr

    rfr New Member

    5
    0
    0
    Good morning all,
    This is a shameless plug really, I hope I haven't breached the forum rules.

    I have been working on a new bolt action rimfire design for about 15 years now and it is time to let the project out for public viewing. Basically it is a front locking rimfire action that is scaled to the cartridge size. In fact bolt diameter is only 11mm (7/16" ish).
    Website is Rimfire Research - Front locking rimfire rifles - Home and is still only pretty basic in it's layout. I am planning to be in small scale production by the end of the year.

    All comments appreciated.

    thanks

    Bruce
     
  2. ScottA

    ScottA FAA licensed bugsmasher Lifetime Supporter

    7,141
    0
    0
    So why the new design?
     

  3. JonM

    JonM Moderator

    20,110
    19
    38
    what is a front locking bolt and how is it better than whats there now?? i read your website but i dont get it.
     
  4. rfr

    rfr New Member

    5
    0
    0
    The new design came about because as a new shooter I couldn't understand the need for a different mechanism in bolt actions to use a rimfire cartridge. In a lever action, or a revolver, or basically any other type of firearm the only difference was the size and position of the firing pin. I also thought that most rimfire rifles were ugly compared to centrefires and that if I could come up with a mechanism that could be either, and wasn't complicated, , then I would pursue it.

    For comparison here is a pic of by bolt in the centre with a 22mag. Top is a CZ527 in 223 and bottom is a Walther in 22lr. The scale difference is obvious.

    [​IMG]

    Bruce
     
  5. Bigdog57

    Bigdog57 New Member

    413
    0
    0
    An interesting idea - I agree, that the bolt does not to be so large as many rimfire rifles have.
    My only concern would be if the rim splits (I have had this happen!) then it's far easier for the small bolt to allow the gases to be directed back to the shooter's face. Does your action provide for this?

    Nice looking rifle - I hope it takes off! :)
     
  6. rfr

    rfr New Member

    5
    0
    0
    Gas leakage is handled the same was as a centrefire. Gas port facing the extractor cut. Most of the rest will go down the feedramp and into the magazine. It was one of my first worries when making the bolt so small, but with the smaller diameter comes good feeding.

    Bruce
     
  7. headhunter

    headhunter Member

    290
    4
    18
    Cute tint thing. How does it shoot?
     
  8. rfr

    rfr New Member

    5
    0
    0
    Both prototypes shot great. the 17HMR model was easily sub MOA from a dodgy home made stock. The 22mag model was about MOA. Both of these tests were done from sandbags on the back of a vehicle, not a bench rest so even though they are a bit crude and don't have premium barrels they are showing good promise.

    22lr production samples being made now are a little more rigid and this time around will have proper range testing from fixed rests.

    Bruce
     
  9. DrumJunkie

    DrumJunkie New Member

    4,823
    0
    0
    From Rimfire Research - Front locking rimfire rifles - Home
    That is a good question. I have to wonder why it was never done. I would imagine that at some point they looked at it and thought the the different design was better but I'm not a gunsmith so I would need to get info from someone much smarter than me. I am very interested in how all this pans out.
     
  10. jpattersonnh

    jpattersonnh Active Member

    5,360
    5
    38
    It is similar to CZ's Micro Mauser design. They also scaled the action to fit the cartridge in the 527 series although that is a centerfire rifle. I would like to see what kind of accuracy these get.
     
  11. JonM

    JonM Moderator

    20,110
    19
    38
    after seeing the pic im wondering about long term durability. the smaller the part the higher the stress it has to endure. i would wager that the reason a lot of gun companies use the larger bolt is they can mass manufacture using cheaper steel and let larger pieces take that stress.

    im just guessing im not an engineer.
     
  12. jpattersonnh

    jpattersonnh Active Member

    5,360
    5
    38
    In that case the CZ527 Micro Mauser action should be a major flop, but instead it has gained a reputation as a superb rifle and superior action to other small bore Varmint guns. You ain't no engineer!;)
     
  13. JonM

    JonM Moderator

    20,110
    19
    38
    is it harder to make a bolt that small?? more or less parts??
     
  14. jpattersonnh

    jpattersonnh Active Member

    5,360
    5
    38
    Same design scaled dimensionally. Smaller in size to lighten the rifle and customize the caliber size.
    CZ-USA -> CZ 527 VARMINT


    98 action bolt and the CZ527 Micro.


    [​IMG]
     
  15. rfr

    rfr New Member

    5
    0
    0
    Long term durability isn't going to be an issue. Current designs are so large not because of stress, but rather due to a carry over of 100+ years of manufacturing necessity. My design overcomes the "problems" of doing a simple front locking rimfire without increasing manufacturing cost or affecting magazine feed. In fact, the cost may even be less in the long term. I can't explain too much of what is different as patents are still being examined and I don't want to throw away the $100k+ that I have spent so far by blabbing too much. :eek:


    The CZ range of centrefires is a good example of scaling to fit a cartridge. Imagine for a minute that there existed a centrefire cartridge with the same dimensions as the 22lr. Would CZ make a new design, or just scale the 527 down even more??

    Bruce