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Thread: Firing pin spring pressure in Bat Neuvo

  1. #1
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    Firing pin spring pressure in Bat Neuvo

    I built a HV on a Bat Neuvo. It shoots quite well.

    One thing I checked was the firing pin drop and spring static pressure. The firing pin drop is fine, around .220 inch. The spring pressure seems a tad light, I checked it at 18 pounds.

    On a whim, I stripped the firing pin assy, and machined a thick enough spacer to get it between 23/24 pounds.

    It sure sounds better. Before it had a clanky sound, after a nice crisp snap. I am going to test it this week end.

    The best way I found to get the two small set screws that lock the firing pin in the cocking piece is to soak the shroud assembly in penetrating oil, then warm it with a air heat gun. They are put in tight with locking compound.

    By the way, it took a .190 inch thick spacer to get the fall from 18 to 24 pounds.
    Last edited by jackie schmidt; 05-09-2019 at 07:46 PM.

  2. #2
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    Maybe.....you want to call Chris or Dwight on that perhaps.

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    Quote Originally Posted by tim View Post
    Maybe.....you want to call Chris or Dwight on that perhaps.
    Every action I have ever had shot better with at least 22 pounds of static pressure. If it shoots worse, I can simply take the spacer out.

    One thing I thing they should do with the Neuvo is make one for a true HV or Rail Gun by doing away with the lightning scallops on the side and the cut away on the bottom. I understand that all of this is performed on a CNC program, it would be difficult to do it for a single ordered action.

    Iím thinking of ordering one for my rail in drop port.
    Last edited by jackie schmidt; 05-09-2019 at 07:55 PM.

  4. #4
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    Quote Originally Posted by jackie schmidt View Post
    Every action I have ever had shot better with at least 22 pounds of static pressure. If it shoots worse, I can simply take the spacer out.
    Only reason I mentioned it is that if you believe all the info on it, much of the concept seemed directed at ignition. Is it possible an iffy spring slipped under the radar ?
    Like you said, not tough to swap back.

  5. #5
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    seems like i read a post from Chris Harris where they were testing pretty light springs with good results
    im talkin 5lbs ive searched and cant find it now

  6. #6
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    Quote Originally Posted by Tim Singleton View Post
    seems like i read a post from Chris Harris where they were testing pretty light springs with good results
    im talkin 5lbs ive searched and cant find it now
    5 lbs? I'm not sure that would fire a primer.

    i have cured more than one erratic shooting Rifle by increasing the pin travel and giving it no less than 22 lbs of static pressure. Early Farleys were some of the worst.

    Years ago, a good friend had a brand new Farley Rifle built. The first time he brought it to the range, it was super smooth and slick, you could just flip that bolt open with your finger. Everybody marveled at the workmanship.

    The problem was you could not make two bullets touch. He was convinced the barrel was bad. We took the Rifle to my shop where I offset drilled the trigger hanger and bushed it back for the 1/8 hanger pins. This moved the trigger back to give the firing pin at least .220 inch travel. I then machined a spacer to give it at least 22 lbs of static spring pressure, which will be about 28 pounds in cocked position.

    The first group he fired after these mods was a mid "one", the Rifle suddenly became a real shooter.

    In my opinion, one of the reasons Pandas shoot so well out of the box is Kelbly builds them with a substantial firing pin travel and 23+ pounds of static spring pressure.

  7. #7
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    Quote Originally Posted by jackie schmidt View Post
    5 lbs? I'm not sure that would fire a primer.

    i have cured more than one erratic shooting Rifle by increasing the pin travel and giving it no less than 22 lbs of static pressure. Early Farleys were some of the worst.

    Years ago, a good friend had a brand new Farley Rifle built. The first time he brought it to the range, it was super smooth and slick, you could just flip that bolt open with your finger. Everybody marveled at the workmanship.

    The problem was you could not make two bullets touch. He was convinced the barrel was bad. We took the Rifle to my shop where I offset drilled the trigger hanger and bushed it back for the 1/8 hanger pins. This moved the trigger back to give the firing pin at least .220 inch travel. I then machined a spacer to give it at least 22 lbs of static spring pressure, which will be about 28 pounds in cocked position.

    The first group he fired after these mods was a mid "one", the Rifle suddenly became a real shooter.

    In my opinion, one of the reasons Pandas shoot so well out of the box is Kelbly builds them with a substantial firing pin travel and 23+ pounds of static spring pressure.
    finally found it
    actually it was in a reply to one of your posts
    http://benchrest.com/showthread.php?...ction-Question

  8. #8
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    Here is how I offset bushed my Farleys to get them to .250 firing pin travel.

    http://benchrest.com/attachment.php?...1&d=1557510352
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  9. #9
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    Quote Originally Posted by jackie schmidt View Post
    i have cured more than one erratic shooting Rifle by increasing the pin travel and giving it no less than 22 lbs of static pressure.
    How do you measure "static pressure"?

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    By static, I mean the spring in the uncocked position.

    Here is a picture. It's not as exact as having a dedicated instrument, but with practice, you can get things pretty close. At the very least, you can tell how much you increased, or decreased the spring.

    http://benchrest.com/attachment.php?...1&d=1557514962
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  11. #11
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    Quote Originally Posted by jackie schmidt View Post
    By static, I mean the spring in the uncocked position.

    Here is a picture. It's not as exact as having a dedicated instrument, but with practice, you can get things pretty close. At the very least, you can tell how much you increased, or decreased the spring.
    So, the "weight" at which the spring starts to compress is the approximate static pressure?

  12. #12
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    Quote Originally Posted by Hunter View Post
    So, the "weight" at which the spring starts to compress is the approximate static pressure?

    I wouldn't call it "weight" nor is it very approximate....... altho Jackie's measuring method is a liddle approximate, it's still brilliant. And an accurate description.

    Picture a spring.....

    it's got a foot of travel an it takes 50lb to fully compress it, bottom it out.

    Now put a 25lb weight on it.

    Where the weight stops is "25lb static pressure"

    Turning the apparatus sidewise doesn't change any of the descriptors IMO.

  13. #13
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    Quote Originally Posted by jackie schmidt View Post
    Here is how I offset bushed my Farleys to get them to .250 firing pin travel.

    http://benchrest.com/attachment.php?...1&d=1557510352
    Jackie, did that create any cock on close?

  14. #14
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    Quote Originally Posted by Wayne Shaw View Post
    Jackie, did that create any cock on close?
    Not on the Neuvo. In fact, it just feels a tad stiffer. The stiffer spring did not affect the Bix and Andy trigger either.

    My Farley HV 30 BR is on the verge. You can feel the cocking piece catch at almost the same moment the bolt starts to turn. When I did the hanger on it, it ended up with .270 firing pin fall.

    Itís just a early R/L, I donít shoot in very fast in the Score format. But it shoots pretty darned good.

  15. #15
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    Quote Originally Posted by jackie schmidt View Post
    I built a HV on a Bat Neuvo. It shoots quite well.

    One thing I checked was the firing pin drop and spring static pressure. The firing pin drop is fine, around .220 inch. The spring pressure seems a tad light, I checked it at 18 pounds.

    On a whim, I stripped the firing pin assy, and machined a thick enough spacer to get it between 23/24 pounds.

    It sure sounds better. Before it had a clanky sound, after a nice crisp snap. I am going to test it this week end.

    The best way I found to get the two small set screws that lock the firing pin in the cocking piece is to soak the shroud assembly in penetrating oil, then warm it with a air heat gun. They are put in tight with locking compound.

    By the way, it took a .190 inch thick spacer to get the fall from 18 to 24 pounds.
    Hi Jackie, I use a lot of these actions. I have about a dozen in the shop now Id guess. They should have about .245" pin fall with no cock on close. Id get a different trigger hanger. Your spring also seems light, from memory the ones I have checked are about 21lb is the cocked position. An excellent ignition design in my opinion. Alex Wheeler
    Last edited by zfastmalibu; 05-13-2019 at 01:21 AM.

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