Improving the Accuracy of a Factory Rifle

Discussion in 'General Rifle Discussion' started by Dillinger, Oct 11, 2009.

  1. Dillinger

    Dillinger New Member

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    Improving the Factory Bolt-Gun: Phase One

    Frequently I answer threads with people wondering what is a good, budget rifle to buy for hunting or entry level target shooting, and the OP wants to know what are some improvements that can be done that don’t cost a lot of money.

    For this thread, we will assume that you have done your research and you have found a bolt action rifle that fits your budget, have found a scope and rings that you like, can afford, and can’t afford ( or don’t care ) to reload at this time.

    Having the scope correctly mounted is crucial, as is having the right length of pull on the stock, to ensure you can squeeze the accuracy out of the rifle that you want. Again, we will assume that you have had this entry level stuff done already.

    1. Trigger Job. I can’t stress the importance of having a good, crisp, clean breaking trigger on your weapon. Trigger pull weights vary by the type of application (as “light” as 2 ounces on a benchrest competition rifle and as “heavy” as 3.5# of 4.5# for a winter edition hunting rifle).

    A really good trigger has very little “creep”. This is the amount of travel from untouched to the point that the trigger has resistance just before the trigger goes to work.

    The trigger should “break like a glass rod” when it goes bang. That is, the pressure should increase very slightly before it “breaks” and the rifle goes off. This process is in reference to having a glass rod, supported between a couple of points and slowly loading weight onto the middle. When the “glass” has had enough, it will not begin to sag, or weaken and crack, it will out right break. Your trigger should break the same way.

    After the break, your trigger should have very little “over travel” before it resets. Most factory triggers have over travel that is considered “extensive”. Over travel isn’t a killer to accuracy, but it will definitely affect your ability to get back on target quickly.

    Trigger jobs come in a couple of forms. Reworking of the factory trigger, or putting in a replacement, after market trigger.

    Reworking of the factory trigger is best left to a professional gunsmith, because you usually are permanently altering the metal surfaces of 2 or 3 levers that make the trigger work. This process usually takes an hour or so and would cost anywhere from $50 to $100 depending on the gun shop.

    Aftermarket triggers come in various forms, usually they are custom designed for your rifle, almost always feature a full three lever design, and come pre-tuned to a specific pull weight.

    Aftermarket triggers are considered “better” but that is not always the case. If your gunsmith is skilled in a good trigger job, he can usually save you a hundred or so dollars by reworking your factory trigger into a great shooter.



    Every gunsmith has weapons in their shop that are either waiting to be picked up, or are their own work. Ask them to try one of their custom trigger jobs.
    • It should have very little creep, a crisp, clean break and very little travel to reset.
    • On a boltgun, it’s important to check for a trigger that is too light and could result in a “slam fire”. This condition is when the bolt is closed aggressively, as if you are quickly chambering another round because you are amped over your deer/elk, and the weapon goes off. If this happens, the weapon’s trigger is TOO LIGHT and is UNSAFE. Any weapon that “slam fires” needs to be reworked until that condition no longer exists.
    If you try one of your smiths’ triggers and it meets those criteria, you have got yourself a good one.

    A reworked factory trigger is always going to cost you less money than purchasing an aftermarket trigger and having it installed. Unless, of course, you got a REALLY great deal on that trigger. :D

    The factory trigger is the easiest, cheapest and should probably be one of your first 2 or 3 changes to improve the accuracy of your recent addition.

    Next: Glass Bedding the Factory Action
     
  2. Dillinger

    Dillinger New Member

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    Next: Glass Bedding the Factory Action

    2) The Glass/Pillar Bed Job

    Most factory rifles do not come with free floated barrels and they do not come with actions that are glass and/or pillar bedded.

    Why is this important?

    A rifle action has a ton of stressors that are placed on it when it is trying to contain a small explosion and force a non-threaded round into a threaded bore of a barrel.

    You see, “rifling” is really the “lands” and “grooves” that you can see in your barrel. The high points and the low points are set in a spiral to get your rifles’ bullet spinning on an axis to obtain the ultimate accuracy. The problem is; when a bullet leaves the brass cartridge, it has NO desire to start spinning on an axis; it has to be forced into that condition.

    At the point that your rifles’ firing pin sets of the primer, which ignites the gun powder, which sends the bullet flying, there is recoil. Your rifle action has to absorb that pressure. The pressure is a back, or North to South pressure, in line with the rifle stock and barrel.

    Now, when the bullet leaves the brass cartridge and is forced into the threads of the barrel, the rifle action is asked to absorb this pressure, which is West to East, at almost the same time.

    Now, most rifle actions have a grand total of ( 2 ) WHOLE action screws that are to absorb all this change in explosive energy, mating the rifle’s action to your rifle’s stock.

    So, how does this relate to improving accuracy JD?

    If your rifle’s action has two screws that mate the action to the stock, and if your barrel is not floated off your stock, it would stand to reason that outside pressures on that stock could influence your action and barrel to do something OTHER than what you want.

    You have to realize, the action is supporting that 22” or 26” barrel you have just hanging out there. You ever try to hold a 26” broom handle out to the side and let your kid, or your dog jump, up and swing on it? Give it a try and let me know how good you are at keeping the handle in line with where you are aiming it. ;)

    Stocks are mass produced. They are not custom fit to your rifle action at the factory that just purchased 100,000 units. It would be nice if that was the case, but it isn’t. And it’s twice as bad if you like a wood stock, because wood swells, cracks and changes dimensions based on a lot of factors, not the least of which is humidity.

    So, how do you defend against that??

    You take a solid rifle action and you build a base for it that is like your hand going into a really comfortable glove. The glove insulates, protects and keeps your hand happy. A glass, and/or pillar, bed job is just that.

    This action creates a custom, hand in glove fit, for your rifle action. The increase is a couple of thousandths’ of an inch, but done correctly, it free floats your barrel from ANY outside influence and it gives the action a complete, custom fit base. When the screws are tightened, that action isn’t going ANYWHERE due to outside forces under ignition.

    A good fiberglass bedding job is probably going to cost you $75-$150 bucks, done correctly, but the results will almost always speak for themselves on a factory rifle. A free floated barrel and an action with a nice, secure, base that won’t move or change under stress of ignition allows for the shooter to maintain more consistency from one shot to another.

    The more things that are the same from one shot to the next leads to tighter groups, leads to better scores and better overall shooting.

    So, there are two, easy, cheap and pretty quick “upgrades” to your factory rifle that, done properly, will definitely tighten up your groups and make your rifle shoot much better.

    JD
     

  3. cpttango30

    cpttango30 New Member

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    Don't forget a recrown job they don't cost much and can enhance accuracy of a factory rifle.
     
  4. stalkingbear

    stalkingbear Active Member

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    Whenever I glass bed a rifle I usually like to bed the rearmost couple of inches of the barrel and then free float the rest. It seems a lot more stable that way and still offers the same degree of accuracy.
     
  5. ItsmeShane

    ItsmeShane New Member

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    i would definitely consider the trigger job, but the gun i am planning to buy here in a few weeks already has a free floating barrel.
     
  6. stalkingbear

    stalkingbear Active Member

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    Hand lapping

    Another valuable accurizing tool that we can do to factory rifles is hand lapping the bolt lugs. Why lap the bolt lugs you ask when the rifle shoots ok as is?

    The simple reason is when the bolt lugs are not contacting the back of their recesses in the receiver the bolt WILL flex slightly. When a cartridge is fired the back thrust on the bolt will flex the bolt until the lugs come in contact with the receiver.

    That flexing causes 2 things. 1 is it causes the action to flex slightly. That very slight amount of "wiggle" wrecks havoc with your zero & bedding after awhile. That's not too much of a problem if the action is bedded solidly into the stock.

    The 2nd is bullet alignment. When the bolt flexes unevenly that MAY cause the bullet to be very slightly cockeyed as it starts down the throat into the bore. This can affect accuracy to a point,depending on how far the bolt lug is away from full contact.

    Rifles with "floating" bolt heads such as savage don't have that problem, perhaps 1 of the reasons they shoot so well for being a cheaply made rifle.

    To hand lap a bolt you'll need
    400-600 lapping compound
    machinist dye or a marker
    gun scrubber or other cleaner to flush the lapping compound away

    First clean all the oil from the bolt & bolt raceway. If you can't, put some of the dye on the back of the locking lugs. Work the bolt several times.
    You should see how much the locking lugs are in contact with the receiver. Usually you'll have 1 lug contacting more than the other (in 2 lug rifles). Now liberally (hate that word lol) apply the lapping compound to the locking lugs. Work the bolt several dozen times, periodically applying more lapping compound. Now clean all the compound off and reapply the dye to the back of the lugs. You SHOULD see an improvement in the area of contact of the lugs. Keep up the above steps as necessary until you see where all the locking lugs are contacting at least 75%.


    Next is hand lapping the bore but I'll let JD explain that.
     
  7. cpttango30

    cpttango30 New Member

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    Here are some pics that should expound on Stalkingbears post about lapping lugs.
    Slide1.JPG

    Slide2.JPG

    Slide3.JPG

    Slide4.JPG

    Slide5.JPG
     
  8. cpttango30

    cpttango30 New Member

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    A close up shot of the second lug.
    Slide6.JPG
     
  9. Dillinger

    Dillinger New Member

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    Awesome pictures Tango!! Thank you for taking the time to show everyone the inner workings of the lugs.

    Really well done!!

    JD
     
  10. stalkingbear

    stalkingbear Active Member

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    Thanks for the GREAT pics tango! A picture really is worth 1,000 words. They explain what I was trying to without success.
     
  11. seenyr

    seenyr New Member

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    Mounting a Tang sight on H&R

    I'm prepping an H&R 45/70 Buffalo Classic for long range Cowboy Action Shooting. Does anyone have a suggestion for mounting a Creedmore tang sight on this? (There is no tang, only stock.)
    Thanks for any input!
     
  12. SirGeorgeKillian

    SirGeorgeKillian New Member

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    Care to explain how?:confused:
     
  13. USN_Sam1385

    USN_Sam1385 New Member

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    What exactly gets done during a re-crown job? Thanks
     
  14. Dillinger

    Dillinger New Member

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    Essentially what you are doing is taking the last couple hundred thou of the barrel and trimming it back, at an angle, to give it a "crown".

    This is a definitive, machined and clean END of the lands and grooves.

    It's not uncommon, because the end of the barrel is banged or bounced during packaging or shipping or unpackaging or placing/removing from the display rack, for the slightest of damage to happen to the crown. If there is a tiny burr or scratch that can impede the bullet on it's rotation out the bore, it will affect it's flight and by way, it's accuracy.

    What is done is the barrel is usually pulled from the action, trued up in the lathe and an angled cut is taken from the very end of the barrel. back enough to eliminate the existing factory crown and making a more sharp, crisp and pronounced end of the threads.

    JD
     
  15. USN_Sam1385

    USN_Sam1385 New Member

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    I see... and does this visually impact the appearance of the rifle barrel?

    Also, can this be done by a local gunsmith, or is it something that the barrel is generally sent out for?
     
  16. Dillinger

    Dillinger New Member

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    Okay, these examples are REALLY pronounced. Normally the start picture is not this tragic and the finish is not this crazy, but it gives you an idea.

    Usually any good gunsmith with a lathe and basic know how can do this procedure. It's usually recommended to get the barrel re-blued as part of the operation.
     

    Attached Files:

  17. USN_Sam1385

    USN_Sam1385 New Member

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    Excellent answers. Very helpful. Thank you much. Given my new rifle appears to be 100% undamaged, this is something that could be waited upon until if/when it becomes visually damaged?? Or would you recommend it anyhow. What is the average cost of this work??
     
  18. Dillinger

    Dillinger New Member

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    On a brand new rifle, unless it was used as a walking cane, it's generally not needed.

    It's easy to check if you need it done, just take a cotton ball and run it LIGHTLY around the crown of the barrel. If it does not snag, you are good to go.

    As I outlined above, there are other steps that would be money better spent on your rifle.

    As for average price on a recrown? $125-$200 depending on the shop.
     
  19. greydog

    greydog Member

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    Since 1972, I would not even test fire a rifle without first glass bedding it. Usually, I prefer to float the barrel all the way but some rifles might benefit from a pressure point.
    Lapping of the locking lugs and seats can improve contact but it is important to be sure it is necessary and to lap correctly. Locking lug contact marks can be deceptive. Most rifles will, by the wear pattern on the lugs, indicate that the lower lug is contacting more than the top. Indeed, the top lug may show very little sign of contact at all. There is a reason for this.
    When the bolt is in battery and the rifle is cocked, contact between the sear and cocking piece lifts the rear of the bolt up until it contacts the top of the receiver bridge. Keep in mind, there is usually a difference in size between the bolt and the bore of the action of from .006 to .011 inch. With the rear of the bolt lifted up, the top lug does not contact. Since most rifles are cycled more empty than loaded, the wear pattern is established and the owner assumes lapping is required.
    When a bolt is being lapped, one should not allow the striker spring to provide rearward pressure on the bolt for the reason described. When cocked, the bolt is held in an attitude of misalignment. Ideally, the barrel should be removed from the action and rearward pressure on the bolt should be provided by means of a nylon stub in a threaded fixture which replaces the barrel for the purpose. Spring loaded fixtures are less desirable since a spring loaded fixture will perpetuate a flaw or even make it worse. I have seen fine pre-64 Model 70 actions all but ruined by improper lapping using a spring loaded fixture.
    If the bolt is fitting perfectly in the receiver and the lugs contacting properly, this happy state of affairs can be derailed if the bedding is poor. If the bedding surface is uneven, the receiver may be warped when the guard screws are tightend up and the lugs will no longer contact evenly.
    The point I am trying to make here is that there is more to lug lapping than meets the eye. In addition, doing it properly requires tools and techniques not available to most hobbyists. Another point is that it is necessary less often than many would have you think.
    Recrowning, done correctly, ensures the muzzle of the rifle is perpendicular to the centerline of the bore. Whether the edge is rounded, flat or angled is immaterial provided it is even and true. Of course, a certain amount of recess protects the crown from damage in the field. Again, it is important to stress the words,"done correctly". A crown which is re-cut poorly is no better than the crown it replaces and may be worse. GD