Barrel Re-Crowning Question

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by blong, Jan 26, 2005.

  1. blong

    blong Member

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    I am going to have a rifle re-crowned, and I was just curious how much a barrel is shortened when you have it re-crowned. Thanks!
     
  2. Guest

    Guest Guest

    depends on how bad the crown is damaged at the most I would say 1/8" unless the end of the bore was damaged from poor hand lapping job then it could be a few inches according to the damage.
     
  3. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Blong,

    If the barrel shot well originally and has been cleaned from the breech end the proper way, I generally only have to take off around 0.020" to 0.030" of barrel length to get a clean sharp crown.

    Who ever you have to it, I recommend you ask if they use live piloted crown cutters. These crown cutting tools are fitted with interchangable bushing that vary by 0.0002" so that you can basically match them to the bore diameter perfectly resulting in a basically perfectly concentric crown to the axis of the bore.

    This job should also not cost much to do so if you get quoted $50 for a recrowning job look elsewhere.

    Why are you looking to have yor muzzle recrowned, just to clean it up or are you having problems with accuracy?

    Good Shooting!!!

    Kirby Allen(50)
     
  4. blong

    blong Member

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    Fiftydriver,

    I was just curious as I have a Rem 700 LVSF in 7mm08 that I would like to make a little more accurate. It always puts the 1st couple shots really close, but the 3rd shot always seems to be about 1/2 - 3/4 inch from them. The barrel only has about 40 rds through it so far (and I have been following a break in procedure). I have read in several places that the best places to start as far as a factory rifle are concerned are the trigger, bedding and crown. I have had the trigger lightened to 3lb, it has been glass bedded (in addition to the pillar bedding it had from the factory), so I figured I would try the crown next (since it is fairly cheap). I was just curious how much I would lose off the barrel since it is only 22" to start with. Thanks!
     
  5. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Blong,

    Unless the muzzle was belled out during manufacturing you should really not loose any meaningful barrel length, 0.020" or so.

    Soudns liek to me that you have a problem with either the bedding or a stress in the barrel that pokes its ugly little head out when the barrel warms up.

    Did the bedding help consistancy any from before to after as far as groups and that third shot opening up?

    Is this a sporter rifle, I assume it is with the 22" barrel length, to be honest, if you are getting consistant 1/2 to 3/4" groups from a factory sporter I would not look a gift horse in the mouth so to speak.

    Sadly this is better then most will do. Recutting the crown will only make sonsistancy better if done correctly so you really have nothing to loose but it sounds like to me when the barrel starts warming up it is either expanding and touching the barrel channel or there is a stress in the barrel that is flexing the barrel as it warms up opening up that group.

    Does it get worse with the 4th, 5th and 6th shot???

    Good Shooting!!

    Kirby Allen(50)
     
  6. blong

    blong Member

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    Kirby,

    I would guess the groups are 1" - 1.5" depending on how close the first 2 shots are. I have never really fired more than 3 shots in a row. Usually I fire 3 shot with a rifle (with about 30-45 seconds between shots) and the I switch to another rifle.

    The barrel is .657" muzzle OD, so it is a little thicker than many of the other 22" barrels I have seen. When I had the action bedded, I also had a couple of pressure points towards the end of the stock sanded off to free-float the barrel, but it seemed to shoot better after the bedding so I do not know if that hurt.

    I will have to shot a 6-7 shot group and see if the problem gets worse.

    Thanks again!