Why do some rifles shoot better dirty?

Discussion in 'Long Range Hunting & Shooting' started by diderr, Oct 30, 2008.

  1. diderr

    diderr Well-Known Member

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    My Remington seems to shoot better and better w/ a dirty barrel. I've gone occasions of not cleaning it for 100 rounds or so, and it will group around .50 c2c at 300 yards. My Ruger will throw shots at around 10 shots; it's a 300wsm frontier rifle.
     
  2. long450

    long450 Well-Known Member

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    That may be true most of the time. I have read some very good shooters proclaim that most people over clean their barrel. With my .223 through .308 no cleaning is necessary for at least 100 rounds. I have shot close to 40,000 rounds of these over the last 15 years and I have a bore scope, so I am not inexperienced. I have had one .338 RUM that required cleaning after only 20 rounds, and it was a smooth Hart barrel. I think the reason for this one was the large amount and type of powder. My theory is to routinely remove the carbon, but only periodically go back to bare metal (remove all copper).

    Then those benchrest guys clean every 10 shots and shoot little bitty bug holes! Go figure?

    Clean at whatever interval gives you confidence.
     

  3. diderr

    diderr Well-Known Member

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    does cleaning have anything to do w? barrel life?
     
  4. long450

    long450 Well-Known Member

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    I can't answer that question with any certainty, since I have not done any study to support that. I will say that improper cleaning will affect a barrels accurate life. Ding the crown and the accuracy will be impacted on a new barrel!

    All of the barrels I have had die did so because of throat wear, which is not caused from cleaning, but from shooting. Using the bore scope you can see the throat begin to crack (much like what you see as a puddle dries up and leaves mud cracked in the bottom). As the cracks get worse, they chip off and alter the pathway of the bullet or the bullet itself and impact accuracy. This condition can be overcome by setting the barrel back to get rid of the throat errosion.
     
  5. Willys46

    Willys46 Well-Known Member

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    heck I hade a 308 that was still shooting great at 250 rounds. I told my self I would clean it when accuracy dropped off. I could not stand it at the 250 mark and broke down and cleaned.

    Another side not..I had a 7rm that shot .75moa most days, some better some worse. I then got into f-class shooting and reading about this terrible thing called copper fouling. I scrubbed that barrel tell there was no copper left. It took many days of soaking with Wipeout. I was so excited to go to the range and shoot the best groups ever! Wrong!! went to a 2 moa gun. I fought it with loads again tell one day I was so pissed I sent down roughly 20 rounds in about 30 min. Talk about hot.gun) At about 15 the thing started grouping up. at 20-25 it was right back to a .75 moa with a smoking hot barrel. Never cleaned again and still shoots .75

    I will say from my experence, factory tubes shoot better dirty and custom shoot better clean.

    Sorry for the rambling.

    Willys46
     
  6. Kevin Cram

    Kevin Cram <b>SPONSOR</b>

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    My 6.5-.284 loves to shoot dirty and hates being cleaned. I normally can go between 100-150 rounds before a cleaning, but when it needs cleaned it throws shots all over. Then once it's cleaned it takes about 10-12 rounds to get it back to shooting consitent. I've got (2) 6.5-.284's and the one I've re-barreled twice and they all act the same way. My .338-.378 will only shoot good for about 30 rounds before it goes south and needs a good cleaning. I imagine it's the difference of 53g for the 6.5 and 106g for the .338. The amount of burnt powder residue left in the barrel and the barrels interior surface finish I believe has alot to do with how long it will perform before cleaning. But then again each barrel is an individual and you must care for each individuals needs. I know my own personal guns well enough that I can tell when they need cleaned and when I can keep plugging away.
     
  7. J E Custom

    J E Custom Well-Known Member

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    To clean or not to clean has always been a hot debate so this is just my
    opinion based on my experance.

    A fouled or seasoned barrel is normaly more consistant from group to group
    but not the size of the groups.

    A clean barrel is normaly more accurate.

    If you clean a barrel every round it will be very accurate if your loads are worked
    up for this type of cleaning.

    If you want to shoot a fouled barrel then work up your loads with the barrel
    fouled with at least 10 rounds fired through the barrel for best results.

    If you have noticed after a good cleaning the first shot hardly ever goes the same
    place as the next 3 or 4 shots.The reason is the oil / solvent is not completly
    removed and velocity is often slightly higher.

    Under most conditions a barrel will be fouled to some degree because multiple shots
    are required like in a match or just working up loads and grouping.Also when hunting
    you cant allways clean between shots.

    When I work up loads I allways clean, shoot 1 fouling shot and then shoot 3 to 5
    shots for group,velocity,sd and es. This way I have a good consistant load for the
    intended use.

    I agree with Willis 46 that most factory barrels shoot better fouled and custom barrels
    shoot better clean but there are allways exceptions.

    The quality of the barrel,the type of powder and the velocity of the bullet all contribute
    to the amount and speed that a barrel fouls so cleaning cycles can vary.

    Which ever way you you elect to clean( Frequent or not ) be consistant .

    The best groups I have ever shot have been with the ,clean and shoot one shot and clean
    before the next shot. But this is impractical so I use the method above so I have 4 or 5
    accurate shots without cleaning.

    This works for me and my type of shooting.
    J E CUSTOM
     
  8. Marine sniper

    Marine sniper Well-Known Member

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    We did some testing of this back in 93-94 at Sniper School. Our primary consideration was to try to figure out a way to predict cold bore shots.

    In general a higher quality barrel will produce a more predictable cold bore shot from a clean barrel. If you played around with how much you cleaned the barrel (just remove powder residue, remove all copper, or remove most of the copper, etc) you could find a "condition" that would produce a repeatable cold bore shot.

    Remember lower quality barrels are usually rougher inside the bore than a Shilen or Hart. It takes a few shots for these imperfections to fill with copper, there by creating a condition. Also remember as this is happening the friction coefficient of the bore is changing.
     
  9. esshup

    esshup Well-Known Member

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    What's the process that you use to work up the load? I realize that you have to clean between every shot, but what do you do other than that?
     
  10. long450

    long450 Well-Known Member

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    Sounds like the need for cleaning frequency is dependent upon the intended use and the type of barrel!
     
  11. J E Custom

    J E Custom Well-Known Member

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    As I have said on other post I am very particular with my loading process and some of the things that I do may not be nessary but I try to leave no stone unturned so that I don't
    have to wonder if I missed anything.

    So hear is the way I work up my loads.

    First I do a full prep on my brass. Polish,Size,Trim,Deburr case mouth,Deburr primer pocket
    and weight sort brass to .05 grain lots.

    Then look at case capacity to determine the primer to start with. 50grains or less I will
    use a standard primer(Non Magnum),50 to 100grains calls for a Magnum primer like the
    rem 9 1/2 M ,And over 100graines of powder I will start with the hotter Fed 215.

    Next I will deside the bullet type and weight I want to use based on it's intended
    use and barrel twist.

    Then comes the powder. I look for a powder that will reach max pressure and velocity
    at 100% case density.

    I start 3 or 4grains below the max and work up .03 grains at a time.

    Load 4 or 5 rounds of each and go to the range.

    I believe in using the chronograph for load development because the first thing I want to
    find is a load with a very low standard deviation(0 to 15).This tells me that I have a good
    powder,primer,bullet weight combination.

    If a load starts out with poor S D's (first 2 or 3 rounds) I abandon it and save the rest of
    that batch for fouling rounds

    Once I have low S D's then I play with primers and bullet seating depths to get the best
    groups at 200 or 300yrds.

    While fine tuning your load only change one component at a time.

    That is why I clean,shoot 1 fouling shot,dry patch to remove carbon,and shoot 3 or 4
    for S D's drypatching only between each shot.

    Before I start testing the next load I do a good solvent clean and start the process
    over.

    Note!! even though you get good S D's your groups may not be good because of bullet
    quality or seating depth ,So I will try other bullet brands of the same weight after I try
    different seating depths.

    Using this method I have managed to get all of my rifles under 3/8ths MOA and 4 under
    1/10 MOA (30/378 .092 ,7 WSM .077 , 7-08 .054 and a 416 buff to .034 ).

    Some of the other guys have other ways of getting good accuracy and maby they will
    chime in and help with some other ways to get the most out of your rifle/pistol loads.

    J E CUSTOM