how can l notice barrel wear?

Discussion in 'Long Range Hunting & Shooting' started by soundwaves, May 14, 2010.

  1. soundwaves

    soundwaves Well-Known Member

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    how can l notice barrel wear by looking at the barrel?

    people say l have to looke at the throught of the barel. were is the throught?

    the end of the gun?

    l own a heym sr 30. 7mm rem mag, how many rounds will l have to fire through it so the gun wont be abel to hit a dear at 400 yards?
    thay say after 1000 - 1500 rounds efects acuracy, but thats probably just a slight amount.
    l wana know how many rounds will it take a 7mm rem mag to be useles at hunting at 400 yrds?
     
  2. liltank

    liltank Well-Known Member

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    Well, I'm thinking the number of rounds can actually be up toward 2000 to 2500rnds considering you shoot factory loads. They are a little lighter than what a hand loader might use. As far as barrel wear, you really need a bore scope. This instrument allows you to look inside with a lighted telescope. You want to look from the breech end and look for deterioration in the throat due to heat. It should looked burned and frayed instead of clean machining. Another thing to look for is heat cracking. It looks like fish scales starting from the throat up through the barrel. Sometimes this can be cut off, and rechambered. It will shorten you barrel considerably though.

    I noticed that mine would not hold groupings with loads that worked well at certain temperatures. 40 degrees would be great. Add 10 degrees and the group would fall apart. I would adjust the load and it would shoot good again. Take 10 degrees or add another 10 degrees and the group would fall apart. Took it to the smith and he found the fire cracking. Hope this helps.

    Tank
     

  3. ovastafford

    ovastafford Well-Known Member

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    Does fire cracking just happen or is it from getting the barrel too hot?
     
  4. elkaholic

    elkaholic Well-Known Member

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    Both! Overheating just speeds it up.
     
  5. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Soundwaves,

    The answer will vary barrel to barrel. Typically you might expect anywhere from 1000-2500 rounds of barrel life in a 7RM. I have shot an estimated 1100-1200 in my Ruger M77 &RM and the throat is cooked according to a gun smith who bore scoped it for me. I shot factory and handloads in it, mostly handloads and they were on the "warm" side... a half grain shy of a sticky bolt. At one time the rifle would shoot a consistent .75 MOA and now shoots about 3-4 MOA. However, there are a few other issues with the rifle that may be the cause of the poor accuracy, not the least of which is being bedded in an older cheap synthetic stock that has compressed over the years and is a terrible platform for the action. I suspect if I put it in a better stock, the accuracy would improve, but who knows by how much?

    I also have a Sendero 25-06 that the same smith bore scoped and he basically said it was one of the worse cases of fire cracking he had ever seen and this rifle is a consistent .5 MOA shooter... sometimes better.

    So the bottom line is that you can only guess when your accuracy will go south. If you want to increase the barrels life, using milder loads will/should help.

    Cheers,

    Mark
     
  6. Boss Hoss

    Boss Hoss Well-Known Member

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    Ahhhhh-----this brings up a good point!

    The Bore Scope is a great tool BUT you have to know what you are looking at. Sometimes looking at something espically in a factory rifle tube one may think that is is actually worse than it is....
     
  7. TerryLamb

    TerryLamb Active Member

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    Previous posters are correct in that there are no simple rules. All barrels/loads will wear differently. It is sort of like searching for a rule as to the mileage at which your automobile engine will be worn out.

    In the end, if your old standby loads begin to consistantly be inconsistent barrel wear could be suspect.

    An old 03-A3 Springfield of mine had always produced phenomenal patterns with a specific load, and gradually those patterns began to disperse. Total rounds fired by me is unkown, but I used to burn through surplus 30-06 ammo, procured in 1320 round cans, over and over. I suspect that bore has seen in the neighborhood of 8,000 rounds fired or more.

    It has never been scoped, but just looking through the bore shows the first six inches or so at the breech end is bald as the proverbial coot. No lands left, smoothbore, period.

    In the end, I guess, bore wear only matters when it begins to affect accuracy.