Effect of barrel contour on long range accuracy?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by smalljawbasser, Jun 9, 2012.

  1. smalljawbasser

    smalljawbasser Well-Known Member

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    I'm in the midst of 7saum build. The rifle will be used for targets past 1000 and big game hunting as far out as I feel comfortable.

    Since I do want to hunt with the rifle weight is a consideration. I have a Montana so I'm not looking for a backpack rifle or anything like that, but I would like to keep the weight to something manageable if possible.

    What effect, if any, do you feel barrel contour/o.d. has in accuracy? What is the smallest contour/weight you would feel comfortable with in this situation?
     
  2. winmag

    winmag Well-Known Member

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    Hart #4 Fluted.
    Id have gone with a lighter weight, smaller contour, but I wanted to reach out there & the #4 contour (fluted for weight not vanity) is what I kept commin back to. Plus to go 26"+, Hart recomends a #4 as the minimum, & I see no reason to go any shorter on a custom LR rig. As you can see in the pic on my signature weight is ALWAYS a concern where I hunt.
    Just seems to be the best compromise of weight vs intended use, & packability/huntability imo.
    Now if its a dedicated LR ONLY rig, heavier is generally better. & if its ELR, heavier is a must.

    My $.02 anyway
     
    Last edited: Jun 9, 2012

  3. ZSteinle

    ZSteinle Well-Known Member

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    Price concerns? Ever think of going with a carbon wrapped barrel? Just got a magnum research barrel (PAC nor liner) for my 7saum build. 1.2 inch tip to tail 27" long 3lbs exactly. reasonably priced at $600. Gives the best of both world IMO
     
  4. smalljawbasser

    smalljawbasser Well-Known Member

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    So are you saying a heavier contour is inherently more accurate? Or inherently easier to shoot accurately because it's heavier?
     
  5. Aldon

    Aldon Well-Known Member

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  6. Jordan Smith

    Jordan Smith Well-Known Member

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    Heavier barrels take longer to get hot, and often stay more stable as they heat up. They can be easier to stay on target with, since they act as more dead weight to "muffle" your heart beat and twitchy muscles. They're not more inherently accurate.
     
  7. elkaholic

    elkaholic Well-Known Member

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    I would go with a 26", 4 or 5 contour, fluted, and here is why. A barrel of this type is capable of nearly the same accuracy as a heavier barrel with the possible exception of multiple shots which we hope we don't need, right?:D The fluting on this size barrel will reduce the weight by approx. 1/2 lb. The most important thing is to have it built by a good smith that will square the action and make sure the chambering is concentric, etc. If you start with a good barrel, there should not be a problem. Some smiths will guarantee a certain degree of accuracy and I would not go to anyone who didn't have a proven record.......rich
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    I get this question all the time from my customers. They say they want all the accuracy possible but in a packable rifle. Then they say they want +1000 yard reach in a sub 8 lb rifle........ Considering thats about the same weight as a Remington BDL, thats asking quite a bit.

    Smaller contour barrels can be extremely accurate and consistant. The heavier the bullet your using, the longer the bullet, the higher the velocity its driven to, the more stress the barrel has to endure consistantly to get the bullets to hit point of aim.

    In my opinion, chambering size and velocity range has to go into consideration. If your building a 270 to shoot 130 gr bullets at 3000 fps, that would require a certain barrel but if your talking abour driving a 338 cal 300 gr bullet to the same 3000 fps, I would not recommend the same barrel for both.

    For your needs, I would recommend a minimum of a fluted #6 contour. Not because anything lighter will not be accurate but because you want to shoot out to 1000 yards and beyond. As such, we need enough rifle weight to dampen your ill effects on the rifle to ruin accuracy.:D Don't take that the wrong way, all of us as the pilots are the weak link in a long range shooting system. In most cases the rifles will do the job as long as we as the pilot does not get in the way of success.

    I like to see a minimum of 10 lbs of rifle weight for any rifle to be used out to 1000 yards. The more the better but this is my recommendation. This amount of weight will help dampen heart rate and breathing, not to mention allow enough weight to settle well on the bipod and rear bag.

    If I were to build myself a rifle for your needs, I would go with a fluted #7 contour and put up with the weight of a 12 lb class rifle ready to hunt with. When its time to pull the trigger you will be happy to have a bit more weight.

    You can certainly make light rifles that shoot extremely well. I have a 7.5 lb 7mm Allen Magnum that just does not seem to miss(knock on wood!!) and I have used it on 28 head of big game from 400 yards to 923 yards with only ONE miss. This rifle has a #3 contour barrel but I will freely admit I prefer a heavier rifle for big game hunting at ranges past 800 yards.

    Hope this helps some.
     
  9. Jordan Smith

    Jordan Smith Well-Known Member

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    Excellent post
     
  10. Mikecr

    Mikecr Well-Known Member

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    I don't really see a need to go extreme on contour -either way.
    Large cartridges need weight to counter recoil & torque, which does affect accuracy.
    But some of this weight can be in the buttstock to balance a gun.

    I go mid weight palma contours, that are long enough for the capacity of the cartridge.
    My 16.5lb 1kyd BR gun holds 3lbs of metal in the buttstock and shoots out of bags like a dream.
    But this is not practical at all for walking field use(or anything else actually).

    You might walk relatively short distances/climbs with a ~12lb gun though. And if your cartridge is not too big, this could be enough.
    ~7lb fluted barrel, couple pounds balance in a light buttstock, Harris bipod, and pretty much any good LR scope other than a NF or US Optics(both wasting weight).