What does my Cooper need?

Discussion in 'Gunsmithing' started by B-RAD, Jun 16, 2011.

  1. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    Cooper Pic Link
    Cooper Load Data Link



    It came stock "bedded and floated", I've adjusted the trigger and it's nice and crisp now. The weird thing is the barrel isn't crowned, would crowning the barrel give me any better accuracy than shown in my .PDF of load data? How about blueprinting? I'm really not sure what is all done at the Cooper factory, so if anyone knows that would be great aswell.

    I came here instead of bothering Dan (Cooper) in his "new" life, He's a damn good guy though, I feel horrible about what happened. (He is doing very well now, about all I can say....)

    Thanks!
     
    Last edited: Jun 18, 2011
  2. screech

    screech Well-Known Member

    Messages:
    1,193
    Joined:
    Nov 26, 2005
    What do you mean by when you say its not crowned? If they didn't crown it id be for getting on the phone. Id shoot it first and see how she does. If it shoots good don't touch it till it needs a new barrel
     

  3. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    Unless there is a microscopic crown on the muzzle.... there isn't one. As for how it shoots... did you look at the pdf?
     
  4. rscott5028

    rscott5028 Well-Known Member

    Messages:
    2,608
    Joined:
    Apr 18, 2010
    It comes blueprinted and crowned from the factory. It likely has what's called a recessed target crown which is anywhere from 0 degrees (flat) to 11 degrees but countersunk about .040-.080" in contrast to traditional 45-60 degree hunting rifles.

    If you're consistently and repeatedly shooting 3 shot groups less than .25" center to center at 100 yds with multiple bullets and loads as implied by your pdf, then you're all set.

    If you're getting .105" center to center consistently, then you're ready to go compete.

    -- richard
     
  5. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,310
    Joined:
    Jul 29, 2004
    Its hard to second guess anyone but if you can't see any crown it might be a clean 90o cut without
    any recess. This is the same thing as a crown it's just not recessed for protection of the crown.

    I have seen this a few times but consider it not a good idea because any kind of contact with
    the "Crown" can damage it and cause accuracy problems.

    Post a picture of it and let us look at the muzzle.

    Without disassembling the action there is no way to be sure if it was Blue printed or not.

    The 1 in 14 twist seems a little slow for a 223 but if it shoots, great.

    Is your load data yours or theirs, and have you grouped it?

    J E CUSTOM
     
  6. rscott5028

    rscott5028 Well-Known Member

    Messages:
    2,608
    Joined:
    Apr 18, 2010
    I don't care if they trued the action with a bastard file and a claw hammer.
    His PDF says he's shooting .105" groups. (@100yds?)
    That's "blueprinted" by my definition.
     
  7. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    under .250" groups are very easy, as for the .105, I'm not ready to compete just yet, I actually had 50 rnds of the exact ammo that made .105 ready to test on paper, but ended up shooting it last week at prairie dogs due to running out of ammo... so in the next few months I plan to do it, just to see if I can repeat that great load. As for the crown it does have what you called a recessed crown, but to me a crown is in the refiling and this surly isn't.



    The Load Data are my loads and groups over the last 2 years, I don't shoot that often as the range is far away, and I don't shoot competition only prairie dogs once a year :)

    Attached is an image from 2 years or so ago of the crown, I can get an updated closer and better picture this weekend if needed.
     

    Attached Files:

  8. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    So what your saying is I can't get any better?
     
  9. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,310
    Joined:
    Jul 29, 2004

    I'm sorry you feel that way.

    I have seen rifles shoot extremely good that were not blue printed. and all that it means is that
    all of the parts that were not square canceled out each other (I in a Million chance) and that is not predictable.

    It works both ways and some Blue printed rifles will not shoot ether but the odds much are better.

    Also the picture of the muzzle shows a crown.

    The reason That I ask the questions is the poster was asking and more information was nessary
    to give him a good answer.

    I doubt that Cooper would ship out a rifle that was not blue printed or crowned but stranger
    things have happened.

    I have also seen targets and group sizes that were sent out by the factory that were bogus
    and misleading. That is why I ask that question.


    J E CUSTOM
     
  10. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    Thanks, I guess I seen a crown as taking off the end of the rifling at an angle, which my rifle doesn't have.

    So basically there really isn't anything I could or should do to this rifle to make it any more accurate?
     
  11. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,310
    Joined:
    Jul 29, 2004

    Beveling the rifling is mainly to make it easier on patches and cleaning from the muzzle (Not
    recommended).

    The idea and function of a good crown is to allow the gas a uniform way to escape from behind
    the bullet at the moment it leaves the barrel.

    If the bevel (if used) or the crown is not absolutely uniform It will have an effect on the bullet
    by allowing more gas to escape from one side than the other, in effect kicking the base of the
    bullet to one side(Off the center line of the bore)destroying accuracy.

    The edge of the bore should be square and clean/sharp. the angle of the crown is mostly a
    personal thing. I like a 11o crown that is recessed for protection.

    The only thing that I would suggest to try and improve the accuracy in an already fine shooting
    rifle is to adjust bullet seating depth a few thousandths at a time in or out and watch for any
    improvements. also check and improve concentricity if your re loads need it.

    J E CUSTOM
     
  12. rscott5028

    rscott5028 Well-Known Member

    Messages:
    2,608
    Joined:
    Apr 18, 2010
    JE,

    I know what you mean and I agree. Unfortunately, sarcasm and dry humor doesn't always go over well in my posts.

    Lots of people have ideas about what constitutes "blueprinting". Some shave a lot of metal here and there and don't really accomplish anything. Others make fine adjustments with excellent results.

    Cooper makes really nice rifles and if it's consistently shooting sub-quarter MOA, I see no reason to mess with the rifle.

    That doesn't mean that the loads/groups can't be improved on. But, for long range, I'd be zeroing in on a single high BC bullet/load and then start practicing because technique and compensating for wind and other elements are the real challenges for practical applications and you aren't going to hone those skills from a bench at 100yds. ...that's a worthy endeavor. But, it's not what LRH is all about.

    Regards!
    -- richard
     
  13. B-RAD

    B-RAD Well-Known Member

    Messages:
    84
    Joined:
    Jun 16, 2011
    Thanks guys I will leave the rifle alone and just work on loads. gun)I'll let you know when I have one .224" sized hole from 5 bullets :D
     
  14. Iron Worker

    Iron Worker Well-Known Member

    Messages:
    1,759
    Joined:
    Apr 3, 2004
    I'd be satisfied with what its shooting now. Our military snipers make hits at extended ranges by learning all about ballistics and trajectory,and whats happening to that bullet in flight. Its one thing to have a 1/4 MOA rifle and another to know where to aim when its 30 degrees up a hill in a 10 mph cross wind at 461 yds. Especially if its shooting back at you.