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Thread: What if there were no MD-PAS ignition?

  1. #1

    What if there were no MD-PAS ignition?

    What if there were no MD-PAS ignition?

    CYA friends:


    What if there had been no Flash Ebert?

    Of course we wouldn't have the wonderful, MD-PAS ignition Turbo action.

    _____________________


    Therefore, what would it be like to live in a SAP ignition only, RFBR world?


    There would be no PSL 12,050 record score, not even close.

    There would be no back-to-back, ARA 2400+ aggs kicked out at the same 6 card match.

    The entire accuracy level of big time RFBR would be much lower than it is today.....


    ____________________


    And another thing.......

    I wouldn't have known about adding momentum dependency to Little Black Knight's PAS ignition.

    ______________________

    This little thing is amazing.

    _______________________


    ______________________


    CYA friends, let's pretend there were no MD-PAS ignition RFBR actions....

    Therefore, to build the best SAP ignition RFBR gun I possibly could, which SAP ignition action would I use?

    The answer is a Falcon, because, although the Falcon uses a threaded bolt shroud, that threaded bolt shroud is stabilized to the breech bolt body.

    And of course the Falcon uses a .750" diameter barrel tenon, and 6 ignition.


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

    If there had never been the Turbo action, would there even be a Falcon action?

    I'm not sure there would be.

    Therefore, I'm going to pretend the Falcon action never existed.

    _______________________


    So now, of the remaining SAP ignition RFBR actions, which would I use to produce the most accurate SAP ignitioned RFBR gun possible?

    This might surprise a lot of you........I'd use a Time action.

    I'll go into why soon...

    Your friend, Bill Calfee
    Last edited by Bill Calfee; 2 Weeks Ago at 08:27 AM.

  2. #2
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    Bill
    You can delete this if this messes up your thread.
    I had hoped you would have chosen the Time. Although I got rid of my Time rifle to be able to acquire my Turbo, I shot some great scores with it. I became pretty proficient at loading and flicking that empty off the bolt face. That big flat portion on my AL sleeved model was a plus. Also the short stiff bolt could be a plus.

    Jerry Halcomb

  3. #3

    Friend JH

    Quote Originally Posted by Jerry Halcomb View Post
    Bill
    You can delete this if this messes up your thread.
    I had hoped you would have chosen the Time. Although I got rid of my Time rifle to be able to acquire my Turbo, I shot some great scores with it. I became pretty proficient at loading and flicking that empty off the bolt face. That big flat portion on my AL sleeved model was a plus. Also the short stiff bolt could be a plus.

    Jerry Halcomb
    ________________________________________________


    Friend JH:

    I'll get into the reasons for selecting the Time action soon...

    The Time can have an ejector............

    It would be similar to the way a Mauser works, or the 03' Springfield.

    If the Time had an ejector, then the loading issue would be greatly simplified....

    One wouldn't have to worry about flicking out the spent case, then starting a round into the cone breech, without a loading tray.

    __________________


    Jeff Patterson has a Time, and I told him we'd look at it one day when we were both free.....

    Yes, an ejector can be done for the Time.

    More later...

    Your friend, BC

  4. #4

    Facebook................

    Facebook................

    CYA friends:

    I'll get back to discussing why I'd use a Time action, if I wanted to build the best SAP ignition RFBR gun possible, shortly..

    But, thank the All Mighty I never got involved with Facebook............

    Your friend, BC

  5. #5

    Why I'd use a Time action

    Why I'd use a Time action

    CYA friends:

    If I had to try to build the most accurate SAP ignitioned RFBR gun possible, here's why I'd use a Time action....starting with the dual firing pins.

    _____________


    First of all, dual firing pins sounds like a kool idea, I mean, if you've got two of something surely it'd be better than just one of something.

    And that'd be the case, if, both of the firing pins led the ignition process simultaneously, I mean exactly simultaneously.

    The problem is, that would be almost impossible to achieve......actually it would be impossible to achieve.



    I don't care how accurately the pin tips are machined, only one of them will wind up leading the ignition process.

    Therefore, if you own a RFBR action with dual firing pins, and the 6:00 pin does the leading, you've got 6:00 ignition..

    If you're unlucky and the 12:00 pin does the leading, well, you've now got 12:00 ignition.



    So dual firing pins in a RFBR action might sound kool, but in reality it's an unworkable idea.......




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


    Since the Time action has dual pins, it's very easy to guarantee that you can have 6:00 ignition.


    Plus, the dual pins can be used to help adjust your case head penetration depth.

    To gain 6:00 ignition in a Time action, all that's necessary is to shorten the 12:00 pin just enough to "guarantee" the 6:00 pin does the leading.

    You don't have to shorten it to the point that it no longer protrudes through the breech bolt nose counter-bore.....( when fired of course)

    ___________________


    In the attempt to drive those dual Time pins, the firing pin spring is about as stiff as the valve spring in a small block chevy...

    Therefore, reducing the spring rate can be accomplished at the same time you're guaranteeing yourself 6:00...

    Caution.....if you completely relieve the 12:00 pin tip so it no longer protrudes completely through the breech bolt nose counter-bore, and don't alter the spring rate, chances are you'll overdrive the 6:00 pin.....

    ___________________


    So one reason I'd use the Time action in trying to build the most accurate SAP ignition RFBR gun possible, is the availability of having 6:00 ignition.....


    But that's not all of the Time's ignition story.....


    More later...

    Your friend, BC


    _________________________

    PS:

    By the way, I was at the range this evening with Jeff Patterson....

    He said something like........man, Chuck Morrell and Big Dog are making it rough on the folks at the Barn, aren't they...
    Last edited by Bill Calfee; 1 Week Ago at 02:24 PM.

  6. #6

    But that's not all of the Time's ignition story.....

    But that's not all of the Time's ignition story.....


    Continuing from my last post....

    _________________________



    CYA friends:

    The Time and Swindlehurst have a commonality; the firing pins are two piece.


    In other worlds, the pin tips, of both, are not directly attached to the firing pin body's, which contain the firing pin springs.


    The big difference, and a plus for the Time, is the Time breech bolt has no front half, like the Swindlehurst.


    When you look at a Time breech bolt, it looks like a 40-X with the front half removed.

    The advantage is, the dual firing pin tips of the Time are very short in length.

    The Swindlehurst pin tip is long, and slides, yes slides, in a slot in the front half of the breech bolt, and is 12:00 ignition.

    And of course the Time can be made into 6:00 ignition, quite easily.

    ___________________________


    Therefore, since the Time's pin tips are not attached directly to the firing pin body, there's no chance of binding between the pin body, where it passes through the bolt shroud, and the pin tips, where they pass through the nose of the breech bolt, like there is in the 40-X style SAP system, where the pin tip and pin body are integral with one another.



    So the Time's pin body, with mainspring, is left to do it's job, and the pin tips are left to do theirs, without the binding characteristics associated with single piece, 40-X style, SAP firing pin systems...



    CYA friends, put another way....


    The single piece, 40-X style firing pin, must pass through the hole through the bolt shroud, and, pass through the firing pin tip hole in the breech bolt nose, at the same time.......

    And this is complicated by the fact, that there's clearances between the threaded bolt shroud and the breech bolt body.

    And then to double complicate this difficult alignment problem with 40-X style SAP ignition, that Remington pattern trigger is applying pressure to the bottom of the cocking piece, while all of this critical alignment is taking place, while trying to produce uniform ignition.


    How 40-X style SAP ignition can be as uniform as it is, sometimes, is a small miracle....



    The Time's SAP ignition system eliminates most of this potential binding, because the firing pin tips are separate from the firing pin body containing the mainspring.


    __________________


    There's still more here.......

    It's 65 degrees and I'm headed to the range....


    Your friend, BC


    ______________________

    Last edited by Bill Calfee; 1 Week Ago at 09:55 PM.

  7. #7

    Another advantage ?

    Hi Bill

    Just thinking could there be another advantage with the duel firing pin concept.

    I will try and explain

    There has to be clearance between the case and the chamber to allow for variations in case diameter and most importantly to be able to get the case in and out of the chamber.

    The case is pushed into position by the bolt so therefore there is clearance for the case to still move forward a little.

    When the case is struck by one firing pin it is on naturally on one side of the case, this will start to move the case forward (as well as start to crush the rim) tipping it slightly because of the clearance and from being pushed on one side.

    Once the ignition has taken place there is a reaction of the case rearwards also pivoting the case around the firing pin.

    On a duel firing pin system with the pins on opposite sides the tipping action during and after ignition could be reduced for a more stable case movement during firing.

    Obviously reducing the chamber clearance helps but you still need some clearance.


    Just Thinking

    Graham

  8. #8

    Friend Deveng

    Quote Originally Posted by Deveng View Post
    Hi Bill

    Just thinking could there be another advantage with the duel firing pin concept.

    I will try and explain

    There has to be clearance between the case and the chamber to allow for variations in case diameter and most importantly to be able to get the case in and out of the chamber.

    The case is pushed into position by the bolt so therefore there is clearance for the case to still move forward a little.

    When the case is struck by one firing pin it is on naturally on one side of the case, this will start to move the case forward (as well as start to crush the rim) tipping it slightly because of the clearance and from being pushed on one side.

    Once the ignition has taken place there is a reaction of the case rearwards also pivoting the case around the firing pin.

    On a duel firing pin system with the pins on opposite sides the tipping action during and after ignition could be reduced for a more stable case movement during firing.

    Obviously reducing the chamber clearance helps but you still need some clearance.


    Just Thinking

    Graham
    __________________________________________________ _


    Friend Deveng:


    I highlighted your last comment in bold yellow........(Just Thinking)

    I enjoy folks who think.

    ________________


    What you're thinking may possibly have merit....

    But here's the situation....

    If dual pins could someway be guaranteed to lead the ignition process equally, exactly simultaneously, which would guarantee there would be 6:00 ignition, then dual pins pinning the case head equally, could possibly be an accuracy enhancement.


    The problem is, it is probably impossible for dual pins to be constructed, so as to lead the ignition process exactly simultaneously.

    Since we must have 6:00, then the prudent thing to do, with dual pins, is to fit them in such a way that we guarantee our 6:00 ignition.

    This means shortening the 12:00 pin enough to "guarantee" we wind up with 6:00 ignition, or eliminating it altogether.

    _________________________


    Something else here:

    It's difficult to drive a single, good, frontal area footprint in the case head........and impossible to drive two.....without a nightmare of a mainspring...

    The Time action, in trying to drive both pins, has a high rate mainspring and small pin tips.

    Reducing the mainspring rate helps to control vibrations.......and resistance to cocking too...


    Therefore, the best use for the 12:00 pin, is to help regulate the depth and size of the 6:00 pin.

    We help regulate the depth of the footprint of a single 6:00 pin, by altering the mainspring rate and the size of the footprint.

    __________________


    The main thing with the Time, since it has dual pins, is guaranteeing we have 6:00 ignition, someway.....

    And the only way I know, is to take the 12:00 pin out of play.


    __________________


    But your point about pinning the case head in two locations, if we could do it and guarantee we have 6:00 ignition, could very well have merit.


    Your friend, BC


    _______________________


    PS:

    Friend Deveng, dual firing pins are an unworkable idea....there's no way I'd fool with dual pins in a MD-PAS, TCA action.


    And I didn't chose the Time action just because it has dual pins.....

    The Time action just happens to come with dual pins, so that will allow me to have 6:00 ignition in my ultimate SAP RFBR build.

    Plus, the Time firing pin body is separate from the firing pin tip, which is a great benefit in reducing the binding issues associated with 40-X style SAP ignition, and its single firing pin which must pass through the threaded bolt shroud and breech bolt nose at the same time.

    Plus, the firing pin passes "through" the firing pin spring with that spring side flexing under compression, binding the pin.

    No wonder SAP rimfire ignition can't kick out 10 round case head penetration test runs, like well blueprinted MD-PAS ignition can.

    ____________


    So the Time's dual pins simply allows me to have 6:00 ignition in my ultimate SAP RFBR build, with a slight modification.

    There's other reasons I chose the Time, which I'll get into later.

    ( By the way, I most certainly didn't chose the Time because of functionality.....it's the antithesis of the Swindlehurst in functionality.)

    ______________________________________


    You know, when you look at the Time action, it looks like someone started to build a RFBR action, got half way, then decided to quit and call it complete......the breech bolt looks like the back half of a 40-X, with the front half missing.

    But, it does have characteristics that will allow it to produce the best SAP ignition accuracy possible.
    _______________________________________


    Last edited by Bill Calfee; 1 Week Ago at 02:51 PM.

  9. #9

    Producing ultimate SAP ignition accuracy

    Producing ultimate SAP ignition accuracy

    CYA friends:

    Please always keep something in mind when we discuss rimfire accuracy:

    The first 95% is a gift that anyone can produce with any reasonable amount of care.

    A person could trip and fall, and on their way to hitting the ground could produce 90% of all the rimfire accuracy there is.

    So making a RFBR gun shoot "pretty good" is a falling down gift, even I can do it.



    It's the accuracy above that first, extremely easy 95% that wins the Big Nationals and set the records.

    And this final percent or two of rimfire accuracy demands the utmost from the schmidt, and, the very best of materials, which include the most uniform ignition possible.

    And as of today, the most uniform ignition is produced by well blueprinted, MD-PAS ignition.


    ______________________


    Also, please keep something else in mind here:

    If I had to produce the absolute best SAP ignition possible, I would use a Falcon action, simply because the threaded bolt shroud is physically stabilized to the breech bolt body, a very clever piece of engineering.


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

    Since we're pretending the MD-PAS ignition Turbo never existed, and if there had never been the Turbo action, I doubt if there would have been the Falcon action.

    Therefore, I only have the other SAP ignition actions to choose from, to try to produce the absolute best SAP ignition accuracy possible, so I've chosen the Time.

    And I seriously believe I could take a Time action, and produce the absolute best SAP ignition rimfire accuracy possible.


    ___________________


    I've already discussed how I'd deal with the ignition of the Time.......

    I would "guarantee" it to produce 6:00 ignition........and in the process I'd be able to reduce the mainspring rate, which is way too much because of trying to drive the dual firing pins.


    But the Time also has the other characteristics necessary to produce excellent rimfire accuracy.

    It has a custom quality action face/barrel thread juncture........the action face is perfectly square to the barrel thread.

    Yes, it does have the giant barrel tenon diameter, but that is easy to reduce to .750".


    The Time has an adjustable head space feature which is worthless, since head space, if one has killer ignition and is safe, has no bearing on rimfire accuracy.

    I used to think it did, that is until I started spearmentin' with it.......and discovered it doesn't.....again as long as you have killer ignition and it's safe.


    And the Time action is stiff.........even with that big cut for a loading port.

    And, it can be easily blueprinted.......it's made of materials that the schmidt can work with.



    Your friend, BC

    More later......

    _____________________________________




  10. #10

    We're in luck...

    We're in luck...

    CYA friends:

    I was talking to Jeff Patterson today....

    He has a Time actioned RFBR gun.....

    So I asked him if he'd mind if I took some pictures of it.

    He said yes...

    Then he told me it was torn down.......which is awesome.

    I wasn't about to ask him to let me remove the barrel, etc.....so I could get some good pictures of just the action...

    ____________________


    So shortly I should have some detailed pictures of a Time action to help finish my discussion of the ultimate, pure accuracy SAP ignition RFBR build.

    We're in luck...

    _________________


    It's sunny bright here today, but still too cold for me to comfortably fool with my new Muller barrel....

    But middle 70's tomorrow....

    That thing's sitting in my lathe ready for me to thread and fit it.......( with an absolutely perfect chamber already cut, blind lucky)

    Your friend, BC

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