How long to break in a barrel

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by bedrok, Aug 30, 2011.

  1. bedrok

    bedrok Well-Known Member

    May 29, 2010
    What's the most rounds you've put through a new barrel to get it shooting it's best? I put well over a hundred rounds through my latest (PacNor, 7mm WSM) including proper break in and it consistanrly shot 2.25 to 2.5 MOA with all my favorite loads. The spread was almost all windage with the vertical spread under .5. At around 125 to 150 rounds it tightened up to approx. 1.25. Now at almost 200 it's usually just under 1. In the past I've never known a barrel to need more than 30 rds. through it to do its best, as long as I've found a load it likes. Any one else experienced this?
  2. rscott5028

    rscott5028 Well-Known Member

    Apr 18, 2010
    1.25 MOA is too much even for a brand new custom barrel.

    Have you discussed this with your smith?

    How did the rifle shoot before the rebarrel?

    Was there any other work done on the rifle?

    Have you been through all of the do-it-yourself accurizing steps? e.g. check torque on all of your screws, make sure barrel is free-floated, nothing touches the barrel while shooting....

    You shot "your favorite loads." But, did you work up a load specifically for this rifle?

    -- richard

  3. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004
    The best barrels normally break in with 10 to 12 shots. some take 15 to 20 but I have seen
    factory barrels continue to foul after 60 rounds.

    I would think that a PacNor should break in after 10 to 15 rounds.

    I think something else is wrong.

    Test: shoot 5 rounds and then clean with a good bore solvent. If it comes clean after 3 or 4
    patch and cleans, It is Broke in. look for another problems.


    BUNDUKI Well-Known Member

    Jul 14, 2008
    i had a pac-nor barrel in 300wm installed on a m700. it behaved in the same way with lateral stringing i tried everything(different scope/rings/bases etc), took it back to the smith twice in the end i traded it in as it never shot better than 1.25moa . got a Kreiger barrel now no problems.
  5. Mikecr

    Mikecr Well-Known Member

    Aug 10, 2003
    Barrels are a crapshoot
    I'd roll the dice again