Loose Winchester Model 100 Barrel / Action?

Discussion in 'Gunsmithing Forum' started by Monsterbuck007, Nov 5, 2016.

  1. Monsterbuck007

    Monsterbuck007 New Member

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    As I understand it the barrel and action should be tight to the stock of the rifle.

    I have a semi-automatic .308 which you can push down on the action below the rear of the scope and it moves slightly. This rifle has accuracy problems. I suspect the movement is the cause of it.

    I've taken it apart to identify the problem and can see no adjustment mechanism to fix it.

    The trigger assembly is held in place by the screw at rear of trigger.
    The barrel and rest of action is secured to the stock by screw in forearm potion of stock (front sling assembly). The front part of barrel is secured to front portion of trigger assembly. This just acts as a hinge allowing the rear portion of action and barrel to move up and down.

    What could possibly be the problem?

    Rear bolt/screw adjustment?
     
  2. danf_fl

    danf_fl Retired Supporter

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    Is this the XP100 or the SPR100? (one is handgun and one is shotgun).

    And the "...front part of barrel is secured to front portion of trigger..." is a little confusing.

    Here is a place to get a manual. https://www.remington.com/support/obsolete-owners-manuals

    Please clarify.
     

  3. SSGN_Doc

    SSGN_Doc Well-Known Member

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    The Winchester 100 is a kind of early semi-auto rifle and many had accuracy issues from what I have heard of them. A lot of this can be from the way they are mounted in the stock. As you mentioned one of the mounting screws is on the barrel, forward of the operating system. Also, the stocks were pretty well hollowed out which leaves little wood to contact the action. Your mounting screw holes may be kind of bored out which prevents the stock and action from sitting together tightly

    The whole concept of how the action and barrel fit into the stock is called bedding. Most modern rifles will bed the action tightly into the stock and may use metal pillars around the screws to hold the action tightly in the stock but distribute some of the force from the tight screws into the pillars and more evenly to the stock to prevent spliting the wood or allowing the action to shift in the stock. Most modern barrels are floated in the stock, meaning that they don't touch the stock at all because a barrel that can vibrate freely tends to have more repeatable accuracy. With some rifles though it s about trying to make the barrel vibrate the same each time it is fired or Ac close to that as possible. With some semiauto rifles the gas system or other moving parts under the barrel can make this harder to achieve. For these guns a pressure pad is used under the barrel, forward of the action to try to isolate the vibration from the action and then allow the barrel to vibrate freely , forward of the pressure pad. Other designs put a pressure pad right near the very muzzle of the rifle.

    Bottom line is that accuracy is about keeping things happening g as close to the same every time the rifle is fired. The Winchester 100 doesn't give a lot of stock material to help make that happen. Then the mounting screw near the mid point of the barrel requires consistent torque loads to be consistent with accuracy. A process of skim bedding and use of bedding pillars may help. There isn't a ton of info in these rifles as far as improving their accuracy, because there weren't a ton of them made, since they were only made for around a decade. Winchester collectors like them because they look very nice and were made in such limited numbers. They also had a recall out in the 1990s because of firing pin problems that could allow them to fire when not in full battery.

    Sorry if that was too much info, or not detailed enough in what you can do to remedy your current problem. Bedding is a simple concept, by can be technical in execution.
     
  4. c3shooter

    c3shooter Administrator Staff Member Admin Moderator Lifetime Supporter

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    Want to try poor man's bedding for a Winchester 100?

    Take a business card, cut into3/4 inch wide strips. Loosen screw that holds barrel to stock, slip 1 strip in between stock and barrel, close to the screw. Tighten screw. Experiment with 1-2-3 strips stacked up.
     
  5. hiwall

    hiwall Well-Known Member

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    What he said^^^.
    You can also move these paper shims to different spots to see what might work best.
     
  6. danf_fl

    danf_fl Retired Supporter

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    Dern, I must have been asleep when I responded.

    There is a difference between Remington and Winchester.

    Why did I read it as Remington?

    Sorry.
     
  7. Monsterbuck007

    Monsterbuck007 New Member

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    sorry to admins. I was trying to find response to this issue and started another thread today (dec 6, 2012) when I couldn't find these posts.

    If this is an early automatic design then its does have some serious flaws at to making it accurate due to excessive movement of the action. I didn't get it for long distance accuracy but for ability to fire in rapid succession at running bucks without loosing sight of them due to recoil.

    I've downloaded parts diagram to see if it was missing anything but diagram is small and can't be enlarged to look for small parts.

    The barrel, action, gas chamber and trigger assembly is secured to the stock by 2 screws and a friction fit. One screw (forward sling swivel) attaches stock to halfway down the barrel. One screw at rear trigger assembly attaches to a recoil mechanism and the stock. The front of trigger assembly which includes clip attachment is loosely secured to receiver with a t-type tang and retaining pin. The poor fit of this assembly allows the receiver and action to swing up around front screw attachment because the rear of the receiver slides into recoil block and is a loose fit. The spring pressure from sliding assembly hold the rear of barrel and receiver into the front of the stock.

    Taking above suggestions I've put a piece of credit card plastic on recoil block assembly with raises it snugly to rear receiver and same thickness piece added in front of forward screw between stock and barrel. Now there is hardly any noticeable movement of rear barrel and receiver with the stock.

    off to the range to see if that cured accuracy problems. previously there was 3 inch movement to the right of bullet hole on 30 yard target of the last shot and previous one with warm barrel.