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Thread: Spring

  1. #1

    Spring

    Mr. Calfee, have you checked your v3 spring at cocked length? I know you have said 8 pounds installed but I dont think I seen if you said at cocked. I may have missed it.
    Thanks, Todd

  2. #2

    Friend Todd Earhart

    Quote Originally Posted by Todd Earhart View Post
    Mr. Calfee, have you checked your v3 spring at cocked length? I know you have said 8 pounds installed but I dont think I seen if you said at cocked. I may have missed it.
    Thanks, Todd

    _________________


    Friend Todd Earhart:


    First of all, I heard you did some pretty good work during the triple crown week.



    Todd, I'm using the older V-2 spring in my V-3.


    I check Turbo spring rates at 1.750" compressed height.


    Here's the way I test.





    Here is the V-2 spring, which is actually 8lb 6 oz.







    Here's a Pepper spring I originally cut down which rates at 8lb.


    Since the older V-2 springs are available, rather than keep cutting the Pepper springs down, I decided to just use the V-2, which is 6 oz greater in rate.

    Close enough.





    Here's a full length Pepper...........I'd tear the rim off if I used this in my V-3, unless I shortened up the pin travel length by a ton, and probably increased the footprint width.


    And then I'd have difficult bolt lift.....


    Todd, this is only a 20 pound scale, so the Pepper is on its 2nd revolution of the dial....

    Look how close the platform is to the top of the scale housing......then look at the difference for the 8lb spring in the picture above.








    Todd, with the V-2 spring, not only do I have fabulous ignition, but the bolt lift is the same, or less, than a two lug Turbo.



    You should have seen Wally's eyes when he lifted the bolt on my V-3, when he was at my shop awhile back....he couldn't believe it.


    Your friend, Bill Calfee
    Last edited by Bill Calfee; 06-13-2019 at 12:23 PM.

  3. #3
    Thanks Mr. Calfee. Im going to order several v2 springs tomorrow. We have a v3 we are working with now for a new shooter. We are really pleased with the way things are going.
    Todd

  4. #4

    Friend Todd Earhart

    Quote Originally Posted by Todd Earhart View Post
    Thanks Mr. Calfee. Im going to order several v2 springs tomorrow. We have a v3 we are working with now for a new shooter. We are really pleased with the way things are going.
    Todd

    ________________________



    Friend TE:


    I'm able to drive my firing pin like I do for these three reasons:


    1. The unbelievable "freeness" of my V-3 ignition system.......

    ( I use the word "my" here, because time will tell if all V-3's are this free....the other two I personally know about, Wally's and Tom's are free too)


    2. I'm running .216" of firing pin travel....

    ( My trigger hanger, since my V-3 is a prototype, did not have the adjustable hanger that comes with production V-3's. So I slotted mine, which gives me a max of .216" of firing pin travel........I understand the factory version will give up to .220" of travel.)


    3. I reground my pin tip to a .033" width.



    Question:



    Will the full .220" of pin travel, combined with the V-3's freeness, and using the V-2 spring, drive the .040" width pin tip like my V-3 drives its .033"?


    It will be close.



    Also, keep something else in mind concerning this question:


    When I took this picture, I was using a cut down Pepper spring, which gave 8 lb's of pre-load, with I believe .010" off my mechanical stop.


    The V-2 spring gives 8 lb-6 oz of pre-load, and I believe I went to .009" off my mechanical stop, which is still OK.......


    I try to stay at least .010" off my stop....I used to have a .005" minimum, but have learned over the years that's not quite enough.






    Todd, here's a prediction:


    If you run the full .220" of pin travel, with the .040" pin width, and using the V-2 spring, my guess is you'll wind up between .012" to .014" off your mechanical stop, which will be just fine.


    I'm adding something here:

    I'm basing my prediction on the fact, that Wally's V-3, with .187" of pin travel, using the standard V-3 spring, and the .040" width pin tip, had the pin .014" off the mechanical stop.

    Therefore, will the additional .033" of pin travel make the difference?

    It will be close.......

    Here's what I'm keeping in mind......this additional .033" of pin travel is off the compressed end of the spring.......033" doesn't mean much off the relaxed end of the spring.




    Keep something else in mind here:


    This prediction assumes that your firing pin protrusion through the counter bore in the breech bolt nose, is identical to mine and Wally's.....which were identical.



    Also, when I screwed a slave barrel into Wally's V-3, I shimmed it to a .043" head space, just like I ran in my V-3 when I tested the Muller modified 4-MI.


    These things must be factored in when determining depth of penetration and distance off the mechanical stop.


    Your friend, BC
    Last edited by Bill Calfee; 06-14-2019 at 12:50 PM.

  5. #5

    Additional.....and a why?

    Quote Originally Posted by Bill Calfee View Post
    ________________________



    Friend TE:


    I'm able to drive my firing pin like I do for these three reasons:


    1. The unbelievable "freeness" of my V-3 ignition system.......

    ( I use the word "my" here, because time will tell if all V-3's are this free....the other two I personally know about, Wally's and Tom's are free too)


    2. I'm running .216" of firing pin travel....

    ( My trigger hanger, since my V-3 is a prototype, did not have the adjustable hanger that comes with production V-3's. So I slotted mine, which gives me a max of .216" of firing pin travel........I understand the factory version will give up to .220" of travel.)


    3. I reground my pin tip to a .033" width.



    Question:



    Will the full .220" of pin travel, combined with the V-3's freeness, and using the V-2 spring, drive the .040" width pin tip like my V-3 drives its .033"?


    It will be close.



    Also, keep something else in mind concerning this question:


    When I took this picture, I was using a cut down Pepper spring, which gave 8 lb's of pre-load, with I believe .010" off my mechanical stop.


    The V-2 spring gives 8 lb-6 oz of pre-load, and I believe I went to .009" off my mechanical stop, which is still OK.......


    I try to stay at least .010" off my stop....I used to have a .005" minimum, but have learned over the years that's not quite enough.






    Todd, here's a prediction:


    If you run the full .220" of pin travel, with the .040" pin width, and using the V-2 spring, my guess is you'll wind up between .012" to .014" off your mechanical stop, which will be just fine.


    I'm adding something here:

    I'm basing my prediction on the fact, that Wally's V-3, with .187" of pin travel, using the standard V-3 spring, and the .040" width pin tip, had the pin .014" off the mechanical stop.

    Therefore, will the additional .033" of pin travel make the difference?

    It will be close.......

    Here's what I'm keeping in mind......this additional .033" of pin travel is off the compressed end of the spring.......033" doesn't mean much off the relaxed end of the spring.




    Keep something else in mind here:


    This prediction assumes that your firing pin protrusion through the counter bore in the breech bolt nose, is identical to mine and Wally's.....which were identical.



    Also, when I screwed a slave barrel into Wally's V-3, I shimmed it to a .043" head space, just like I ran in my V-3 when I tested the Muller modified 4-MI.


    These things must be factored in when determining depth of penetration and distance off the mechanical stop.


    Your friend, BC

    __________________________________________________ _____



    Additional.....and a why?


    CYA friends:


    A why, first.


    Wally's V-3 is ready for a barrel.......


    His action is driving a .040" wide firing pin, keeping it .014" away from the mechanical stop.


    His V-3 will produce killer ignition, and will extract every bit of accuracy that the barrel he's going to put on it is capable of, if fit properly.


    So why change anything?


    He doesn't need to.....


    His bolt lift, as is, is very acceptable....


    He has killer ignition, as is.



    So why even contemplate changing anything?


    __________________________



    CYA friends, we're benchrest shooters........at least I am, as are most of the folks in my circle of personal friends.


    Benchrest shooters, true benchrest shooters, centerfire or rimfire, are never satisfied.....


    Benchrest shooting's main objective is to advance accuracy.


    So even though Wally doesn't need to change anything about his V-3, if I owned it I would.


    Cause I ain't never satisfied.



    ____________________



    Now, some math.....which I'm not any good at:



    Could Wally drive his .040" wide firing pin tip with the V-2 spring.......( this also parallels what Todd and Tad Earhart are working on)



    My .033" wide pin tip is 17.5% easier to drive than Wally's .040" wide tip.


    If Wally were to increase his firing pin travel from .187" to .220", he will increase the striking force by 15%, mathematically.


    But.....................


    Since the .033" increase is on the compressed end of the spring, the actual increase in striking force is greater than 15%.....


    And how to figure how much greater I have absolutely no idea.......I just know it's greater than the mathematical difference.



    Therefore, I feel Wally's V-3 can drive its .040" wide pin tip with the V-2 spring.........same with the Earhart's.



    _____________________



    Now here's the big gain.......extremely easy bolt lift.......although Wally is well satisfied with it the way it is.



    There's one other difference, that I feel sure will happen:


    I'm not over driving my .033" width pin tip.......and I'm .009" off my mechanical stop...


    I still believe the .040" wide pin tip will wind up in the .012"-.014" range off its mechanical stop.


    Which is better?.........or is it a wash?


    Probably nearer a wash, but, time will tell........this is what makes benchrest shooting so fascinating, rimfire or centerfire.


    Your friend, BC

  6. #6
    Testing is a large part of the fun to us. Its great when you find some gains and stinks when our ideas dont pan out. Everything cant be gains and that keeps me interested. Looks like sunday will be the first rounds fired from the v3. I look foward to it.
    Todd

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