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Accurizing ??s.

Discussion in 'Mosin Nagant' started by Mkrauss, Feb 16, 2017.

  1. Mkrauss

    Mkrauss G&G Newbie

    I understand and have completed most of the fine tuning that can be done on a mosin. Trigger, Barrel recrown, freefloating stock, . The last two things I was going to do were pillar and glass bedding. Can someone tell me exactly what the advantage of bedding is. I understand how to do it but why does it make the gun more accurate. Every time you get set to take a shot you line up the front and rear sight. These never change. They are fixed to the barrel/ wouldn't matter.if the stock moved balf an inch since the previous shot. I am exaggerating but seriously what dont i understand about it. I am fairly new to all this so bring on the knowledge. Thanks
  2. TACAV

    TACAV G&G Evangelist Forum Contributor

    When you have your action installed in your stock without the bedding, it might not (probably won't be) a perfect fit and even after you tighten everything down in there you create uneven stress points around the screws/bolts or whatever. The action is sort of... I don't want to say "floating" but it's not in even/consistent contact with the stock throughout it's length. it might be pushing more against the stock in some places like around the attachment points to the stock, and less or not at all in other places. we are talking very small tolerances here.. but these willl cause flex which then cause accuracy loss. When you bed the rifle you are making everything fit nice and flush together so there is less stress points on the action and thus there will be minimal flexing when you fire the gun... or at least keep any remaining flex consistent throughout each shot.

  3. Mkrauss

    Mkrauss G&G Newbie

    So it is more about flex than anything else. I was thinking it was more about keeping everything in the same location. Lack of movement i guess. Glad to learn more. I guess i will go ahead and do it then.
  4. Big Dog

    Big Dog Retired IT Dinosaur Wrangler Forum Contributor

    While bedding the receiver can be beneficial, bedding the barrel likely will hurt. It rarely works with long military stocks with upper handguards. Floating the barrel is usually better, though again difficult with the handguard.
    With standard sporting stocks, I bed the receiver, then use a small pressure pad at the front of the stock.
  5. tobnpr

    tobnpr G&G Enthusiast

    Correctly done, bedding provides a precision stock to action fit that eliminates receiver stress in the action and maximizes consistency/precision.
    Without it, especially outside a precision chassis, when you torque the action screws you're bending the action. Epoxy bedding creates a perfect female "mold" of the receiver so that it cannot bend/warp. It's not a matter of the sights-of course they don't move. It's about keeping consistent harmonics of the barrel/receiver as well so that the barrel "whip" is exactly the same every shot.
    ChaZam likes this.
  6. Rocky7

    Rocky7 G&G Evangelist

    What he said.
    ChaZam likes this.
  7. Dennis

    Dennis G&G Evangelist

    If you where to put a high speed camera on your rifle while it fired you would see all sorts of movements the slight bulge in the barrel that goes down the barrel behind the projectile.
    The flexing of the receiver barrel and stock and how they are All moving differently
    It is a bizarre thing to see.
    An AK looks like it is made of rubber when it shoots....
    Rocky7 likes this.
  8. shop tom

    shop tom G&G Evangelist Forum Contributor

    Have you slugged your barrel to verify the exact bore size? Do you hand load for it?
  9. mickykl3

    mickykl3 G&G Newbie

    I am also confused about that.
  10. Junction15

    Junction15 G&G Evangelist

    This is just saying the same thing others posted:

    You might think of accurizing this way: When a firearm fires, a tremendous amount of pressure is built up inside the barrel & action. The gun will snap into different positions, the barrel will flex, all sorts of things happen during that split second.
    If the gun always flexes the barrel the same way, and snaps into the same exact position, then each shot should go into the same spot. Adjust your sights to line up where the bullet hits and you're golden.

    Firearms often have large tolerances (relatively speaking) in the way the parts all fit together. So when fired, all those flexes will likely be different and the action will snap into slightly different positions each time. Small changes in where the gun is pointing as the bullet exits the barrel adds up to bigger groups downrange.

    If you can re-work your gun so the tolerances are tighter, and either restrain the barrel to decrease the flexing, or free-float the barrel for more consistent flexing, the differences in where the barrel is pointing as the bullet exits will be smaller.

    Of course, this only addresses the firearm itself. Then factor in ammunition, shooting technique, wind changes, sights, and other factors with that and we can see the challenge of making one small hole with many shots is tough to do.

    Addressing the other part: Slugging the bore is really just forcing a lead bullet through the barrel and measuring it. This tells you the exact size of the barrel so you can make or buy bullets that fit your bore better. That leads to better consistency in how your ammunition behaves with that firearm.