Rough Spot?

Discussion in 'Sako Long/Magnum Actions' started by wombat, Oct 20, 2020.

  1. wombat

    wombat Well-Known Member

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    Hello,
    I think I might have a problem? I have an L61R in 7RM. S/N 811**, I have shot a good Hunting group
    Of about 1.25” using Win brass and 61.5 gns of RL22, using 175gn Hornady SP projectiles.
    Just trying out other projectiles the groups are now about 2 _ 2.5” and sometimes even a flyer.
    When cleaning the barrel, just a patch with solvent (Hoppes) I notice the patch “grabs” about 10” forward of the chamber as if there appears to be a slight rough patch in the rifling?????
    I have not used a proper bore scope, but when I look down barrel with bore lite from one end, and even with a magnifying glass the rifling appears bright, shiny and sharp all the way and I can see no blemishes or dark spots??? I can also feel the rough patch with the bronze brush.
    Has anyone ever come across this or similar, and if there is any advice on what I may need to try next!
    Maybe bore brite and a solid Lap n polish?
    I will be interested in any comments.
    Jay

     

  2. piper235b

    piper235b Well-Known Member

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    Hi Wombat,
    Pretty hard to be sure without looking with a borescope, BUT I've bought some rifles with a powder build up in that area, and experienced it myself after a big day's shooting. And the patches will grab there like it's a rough spot. Say an area 25-100mm (1" to 4") long; varies between rifles.

    Even the best solvents take forever to shift it, so I cheat and use either JB Bore paste (the cleaning one, not the lapping one) or my favourite KG-2 Bore Polish. Both knock that crap out fast and the bore looks wonderful afterwards.

    Even if it does turn out to be pitting, don't worry, most still shoot quite well, I've owned some very good shooters that had terribly pitted bores.

    If ever you get let out of Vic, and you're coming up the Hume to Sydney (I'm near Mittagong), give me a shout beforehand and I can check it with a borescope. Alternately take it to your friendly gunsmith and he'll take less than 2 minutes to check it and let you know the verdict.

    Cheers
    Piper
     
  3. 16b410

    16b410 Well-Known Member

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    If you are shooting 5-shot groups into an inch and a quarter with a big 7 you don't have what anyone would call a real problem. But if you want to know what it is you are feeling (like I would) scope the barrel. If it is damaged, it is what it is. If it is fouling, I like the Bore Tech products. I keep Eliminator as the all-purpose and also have the copper killer and carbon killers they offer as well.
     
  4. paulsonconstruction

    paulsonconstruction Sako-addicted

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    You need a more aggressive bore solvent & a bronze brush. The "rough" spot you feel is probably fouling. Clean it, then clean it again scrubbing the bore with the brush. When you can run a tight patch with solvent back & forth through the bore without resistance, try shooting it again. The bore should feel slick when it is clean.
     
  5. wombat

    wombat Well-Known Member

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    Thanks for advice guys, sounds like the consensus is a bit more aggressive cleaning, I will get onto it and get back with how it goes.
    Jay
     

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