Results 1 to 4 of 4

Thread: PAS ignition spearment

  1. #1

    PAS ignition spearment

    PAS ignition spearment

    CYA friends:


    Man, wouldn't it be so cool for our 40-X friends to be able to have PAS ignition........

    What would be even cooler, and of more interest to me, would be for me to have PAS ignition for my #14 pistol...

    ___________________________


    Here's what I'm up against:

    I've got to be able to drive a 2 ounce TCA firing pin, with 1/2" less firing pin spring room inside of the firing pin...

    The 1/2" must come off the rear half of the breech bolt......

    By the way, there's absolutely no doubt that PAS ignition can be driven in the 40-X breech bolt.....

    __________________________


    Anyway, the prudent thing for me to do, before I go to all the trouble to build a PAS, XP breech bolt, is to discover whether I can drive the TCA pin, with 1/2" less spring length....

    By the way, even though I have 1/2" less firing pin spring room, I've calculated, that I don't have to shorten the TCA spring a full 1/2"...

    More like .430" will have to be removed....

    __________________________________________


    Below is a picture........

    What I'm going to do, is to shorten the spring in my 10-X triple, then see if I can drive the pin properly.....

    I've already made up a spacer, and, I'm also going to try an assist spring.....if necessary......

    If I can make this new spring system drive the pin, with any sort of moderate bolt lift pressure, on my triple slave.......then on a 90 degree lift XP the bolt lift effort will be a snap...

    More later.....

    By the way, the first test will be to see if I can duplicate the firing pin penetration depth with the shorter spring(s)...

    If I can, the second tests will be to run 10 round penetration tests......( I already know what my slave triple will do, as is)


    Your friend, Bill Calfee

    _______________________________________


    By the way, I've not shortened the Pepper spring, or, the assist spring yet.....I'm going to double check my calculations first...

    One issue is, the coil spacing is different on these two springs......bc


    Last edited by Bill Calfee; 1 Week Ago at 06:34 PM.

  2. #2
    In engine building for Karting mapping springs is everything because of controlled valve float. We used a intercomp spring tester /part no. 100058. I now use it for checking firing pin springs. We would test100s of springs looking for the magic ones. Wish I was closer and you could borrow it. It is very interesting what you find. Not all springs are created equal. Todd

  3. #3

    Friend Todd Earhart

    Quote Originally Posted by Todd Earhart View Post
    In engine building for Karting mapping springs is everything because of controlled valve float. We used a intercomp spring tester /part no. 100058. I now use it for checking firing pin springs. We would test100s of springs looking for the magic ones. Wish I was closer and you could borrow it. It is very interesting what you find. Not all springs are created equal. Todd
    _________________________

    Friend Todd Earhart:


    Thank you for the advice.....

    Todd, the first thing I must do, is determine if it's possible to drive a 2 ounce TCA firing pin with a half inch shorter spring....

    If, I discover that it is possible, then refining the spring(s) needed, may, or will, be in order.....

    _______________________


    But right this moment, I've got to find out if it's possible to drive a TCA firing pin with a half inch shorter spring, or, is it just a pipe dream...

    Yes, I wish you were near by......not many folks, today, are seriously interested in advancing rimfire accuracy.....

    Your friend, Bill Calfee


    __________________________


    I've got a lot of work to do........and, it's way too important that I do.....bc

    _____________________________


    Last edited by Bill Calfee; 1 Week Ago at 11:19 PM.

  4. #4

    Spearment update....

    Spearment update....

    CYA friends
    :

    I've been trying to figure, exactly, how long my short spring for XP PAS ignition needs to be....

    See, from the end of the counter bore in the firing pin, where the end of the main spring purchases, to the firing pin spring retaining pin, where the other end of the spring purchases, is slightly longer on the 40-X PAS ignition than on the TCA's....

    In other words, the 40-X PAS ignition, using a standard Turbo main spring, will need a small spacer installed, to bring it to the same compressed length, when at battery, as the Turbo.

    ______________________

    The same ratio applies to the XP......

    So, before I ruin too many springs, guessing, I've spent all morning calculating the exact compressed length, at coil bind, that I will need for my XP PAS ignition......

    And then I have to work out the same thing for the assist spring, if needed, which is even more complicated as the coil spacing is different than the standard TCA springs...

    Your friend, Bill Calfee

    __________________________________




Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •