Cold bore shot vs dirty bore shot

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Wachsmann, Apr 22, 2012.

  1. Wachsmann

    Wachsmann Well-Known Member

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    Hello,

    I have a savage 116 stainless flutted in the 6.5x284 accura trigger accura stock. My question is about my first cold bore shot is slower in volecity and it shoots about 1 to 1.5 inches low. After the first shot, with my reloads its a .5 to .7 inch shooter all the way to 20 plus round durring a shooting secission letting the barrel cool after each shot. I alway was told the first cold bore shot will or should be your best and fastest shot. Could someone explain?
    I fell that before I go hunting with this gun i better get the barrel seasoned with one shot down the pipe.
     
  2. Mikecr

    Mikecr Well-Known Member

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    I've never seen a cold barrel shot faster than a warm barrel shot. What you're seeing is normal IMO.
    Prep for what you need. If it's clean cold barrel, fouled cold barrel, warm barrel, hot barrel whatever. You can also pre-foul a bore with something like WS2 as part of your cleaning routine, to get the first cold shot with others.
     

  3. LouBoyd

    LouBoyd Well-Known Member

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    Typically lower engraving forces result in lower velocity though it can go either way. Shooting with a "clean" barrel vs a fouled barrel with everything at the same temperature should show if that's the problem. A clean but lightly lubricated barrel can perform very different from a clean dry barrel. I prefer to not clean a barrel if I'll use it again soon. I'd never shoot a match without sighter/fouling shots where they're allowed. Sighting and fouling shots can be just as useful for hunting.

    The temperature of the powder in each cartridge at the time it's fired will also effect their velocity Firing a rifle can also effect the point of impact relative to the point of aim from thermal bending of the barrel, action, base, rings, or scope. With simple tests at a range with a chronograph and a little thought the cause of point of impact movement can be sorted out.

    I've taken a heat gun to the range a few times to find stubborn thermal sensitivity problems. They make sense after your find them. Having a steel action and an aluminum scope at different and varying temperatures tightly tied at two locations with rigid rings is just asking for bending problems, particularly if the bases don't fit the action properly.
     
    Last edited: Apr 22, 2012
  4. 7stw

    7stw Well-Known Member

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    What you are experiencing is fairly normal for the most part. Whenever I go to the range to practice, or when developing a load, I always take a few " fouler" shots before getting serious. Most factory, and even some custom rifles are that way also. As far as hunting, and with that knowledge that the first shot, cold and clean is going to be out of the group, just sight your rifle the day before, or just shoot a few foulers. That way, the bore is " slightly" fouled. I have done that for years anyway. I wouldn't worry about it, or think into it at all. Enjoy!!!!
     
  5. Wachsmann

    Wachsmann Well-Known Member

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    Thanks for the tips. I read some other post and it sounds like cleanning the barrel back to bare metal compared to a fouled barrel can make a world of difference on non custom barrels. I also may be leaving to much oil in the barrel after cleaning and then shooting. I try cleaning and swabbing several times till the patches are completely dry and shoot. But for as the rifle its been a good shooter after that first cold shot. I usually wait about 3 minutes between shots as well.
     
  6. Bart B

    Bart B Well-Known Member

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    It's been my experience that most factory barrels are a bit rough and it takes a few fouling shots to fill in their micro pits until jacket material no longer gets scraped off bullets and unbalances them.

    On the other hand, top quality match barrels are lapped smooth enough that the first shot from a clean barrel and subsequent shots are within 1/4 MOA of each other. This happens from shot to long range and the vellcity diffrence between the first two and the rest of the 15 to 20 shots is usually less than 10 fps.
     
  7. J E Custom

    J E Custom Well-Known Member

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    All barrels are different. Some like a clean cold barrel others like a slightly fouled barrel
    that is cold.

    I have had both and one of my favorite rifles likes one fouling shot followed by a dry patch
    just to sweep out the barrel. Then it is ready to go hunting.

    A clean barrel lightly oiled changes the POI on some rifles and it is wise to know what your
    rifle likes best through experimentation.

    One reason I like the stainless barrels is that they don't have to be oiled every time you
    shoot them and if they need a fouling shot it is ok to leave it that way for a short time.

    I like to use the bore snake for this and carry one with me on the hunt so that after a shot
    I can sweep the barrel and I am ready to make the next shot with the barrel in it's favorite
    condition.

    J E CUSTOM
     
  8. Greyfox

    Greyfox Well-Known Member

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    While my primary LR rifle shows virtual no difference between clean, cold fouled , and hot fouled, I prefer to hunt with a fouled barrel. My other rifles need to be fouled. I only clean after 20-30 rounds or so, or if the rifle is subjected to high moisture conditions. Leaving nitro based fouling in the barrel for the duration of a hunt, or season will not cause barrel corrosion unless it gets damp/wet, and goes unfired for a extended period. I think you are ok with your fouled bore set up. I would also try a couple of multi shot groups without letting the barrel cool between shots. This could be a field condition should an accurate follow up shot be required. IMHO.
     
  9. Mikecr

    Mikecr Well-Known Member

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    I've concluded based on my experience that barrel performance in this regard cannot be predicted or assumed. I've seen barrels(including best in aftermarket) throw cold-clean shots relatively far from fouled-warm shots to follow.
    It's exactly why competitors get sighters.

    It just needs to be verified and possibly adjusted for with your planned condition to shoot at game with. Your not gonna have sighters in the field to fresh foul and bring any barrel to stable temps. The best you can get is cold pre-fouled. Also don't forget to test off a bipod(in the dirt) if that's your field rest.
    It can take a lot of discipline to validate this, and even more to adjust for it I know. But it's worth it when you can pull the gun from your safe, ground the bipod, and know your first shot will be as good as any.
     
  10. Bart B

    Bart B Well-Known Member

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    All the better aftermarket centerfire barrels I've shot and seen used in competition since the 1960's shoot within 1/3 MOA for the first 5 shots through 600 yards, within 2/3 MOA up to 1000.

    Competitors in high power competition have been getting sighters in some matches but not in others since the early 1900's because the wind cannot be controlled by the shooter. Sighters were never allowed based on equipment behavior because that can be compensated for by the shooter. Competant rifle shooters know how their first few bullets fly relative to the others fired later.
     
  11. Broz

    Broz Well-Known Member

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    Keep in mind that cleaning practices will greatly effect your first round POI after cleaning. What you use for cleaning solution, and what you use in the bore is what I am talking about. If you aply oil to the bore how could it shoot the same as it does dry? This is why some shooters need to "foul" or I say "dry out" the barrel. I have worked with two of my long range rifles and they now shoot cold bore clean the same as they do after 20 shots through them cold bore. They will hold to within the 1/2 moa capabilities of the rifle, load and my skill level.


    Jeff

    Orange circle is 7"

    [​IMG]
     
  12. Mikecr

    Mikecr Well-Known Member

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    I can think of no sanctioned competition where sighters aren't built in.
    And I doubt a competitor would include a cold shot with record shots.

    But I'll look at the rules again & poll BRC to confirm.
     
  13. Bart B

    Bart B Well-Known Member

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    Check out the NRA's high power rule books as well as the CMP ones for service rifle matches. Then get some match programs from match sponsors to see what matches sighters are allowed in and which ones they are not. You'll see that:

    Service Rifle Excellence in Competition Matches (to get points towards earning the Distinguished Rifleman/Marksman gold badge) do not allow sighters; every round fired counts. Even those from a cold, clean barrel. These are fired at the Nationals, regionals and some state matches as well as matches within the Armed Services at their ranges.

    At the CMP Nationals, the Presidents Hundred Match allows two sighters at 200 yards for the standing stage, but none for the 300 yard rapid fire nor 600 yard slow fire stages. No sighters either in the National Trophy Team Match nor the National Infantry Trophy Team Match.

    In NRA local, state and regional and National matches as well as Military Local and Major Command Matches, sighters are typicaly not allowed in most team matches. Sighters are allowed in some, but not all, individual matches. When allowed, there's typically two at the start of each stage. Long range matches fired at ranges greater than 600 yards have either two or unlimited sighters depending on the specific match and program rules. And some long range team matches allow two sighters per shooter for each stage.

    Now you can think of sanctioned competitions where sighters are not allowed.
     
  14. Mikecr

    Mikecr Well-Known Member

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    Thanks
    And of IBS and NBRSA?