shotgun patterning questions.

Discussion in 'Large-Bore/Small-Bore Rifle/Shotgun' started by johnlives4christ, Apr 23, 2009.

  1. johnlives4christ

    johnlives4christ Former Guest

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    i have an 870 police model. i have shot some differant broad targets in order to get an idea of the shot spread, using mostly birdshot. it seems to always hit a tad high and left. i heard an experianced shotgun shooter say once that if you filed the end of the barrel just a tad it would change the center of the shot pattern. does anyone know of doing this or anything else.

    thanks

    ~john
     
  2. Big ugly

    Big ugly New Member

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    I had a civilian 870 and it shot the same. For those of us scattergun ethudiest that go out turkey shootin we usually just adjust our aim to compensate for the shot pattern. You can try to adjust the shot pattern but I would advise not with a file. If you must, take it to somone and have it backbored and sleaved. How far away fron the target are you shooting?
     

  3. johnlives4christ

    johnlives4christ Former Guest

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    im working various distances out to 25 yards. the file idea seems sound to me, but its the only time i've ever heard of it
     
  4. Big ugly

    Big ugly New Member

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    I have heard of folks doin it with mixed results. I just hate buggering up a good barrel on a maybe if you get my meaning. Something else I found too is look at wht type of shell you are useing. I would mabbe try a different shell type too. What guage is your barrel? Or choke if you will? Like some will be a 675 guage or a 685 if it dont say that then it should say Full or Modified.
     
  5. johnlives4christ

    johnlives4christ Former Guest

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    well i have an 18 1/2 bbl that i cut down from 20 inches, so i wouldnt worry so much about messing it up, i got it square as my eye can tell and took the sharp edges off.... it is a cylinder bore barrel.
     
  6. Big ugly

    Big ugly New Member

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    Ahh well that explains a lot. File away from the pattern a little at atime and fire frequently to see where the pattern is going. Adjust the filing as needed. Also you might try using some type of abrasive like sand paper first though that way you dont groove mark up the barrel too bad.
     
  7. johnlives4christ

    johnlives4christ Former Guest

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    by file away from the pattern you mean, if its hi, file the bottom of the muzzle?

    i have had a gunsmith put a bead on it for me, its not very important that it hits dead on , but since i dont have much else to do, i figured i would tinker around on it, get it right, and in the process i figured i might learn something too. always a good idea in my opinion, especially with this bad political climate, to be able to smith ones own gun if need be.
     
  8. Big ugly

    Big ugly New Member

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    Yeah file away from the pattern.
     
  9. army mp

    army mp Member

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    I am not saying this is the problem, but a few years back I had a guy tell me he and a gunsmith friend were having trouble, sighting in a mossberg 500 that they had put a slug barrel on. When I got the gun they had filed the rear sight out. Well I had to put the gun in a vice to get the Barrel nut off. Instead of backing the Mag tube out to take up the gap. Between the barrel and mag tube, They just tightened the barrel down as tight as they could get it. This pulled the barrel down. I am a firm believer. Get it checked out by a qualified gunsmith before you start filing.
     
  10. GMFWoodchuck

    GMFWoodchuck New Member

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    Uh...Instead of buggering the barrel. Get another barrel. Filing the inside of a barrel sounds pretty bad to me. A new barrel doen't cost that much. Besides, you'll end up with a barrel that is more appropriate for hunting with and you'll be able to pick the choke of your choice instead of beside limited to an Imp Cyl choke. If you can't afford to do that. At least take the barrel of and reinstall it. That always changes my point of impact on my shotguns much to my dismay. But it could be to your advantage.
     
  11. carver

    carver Moderator Supporting Member

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    If you just cut off a barrel, then you also cut off the crown. What you should have done is put the front sight on yourself, that one's a no brainer. Then had the gun smith cut off the barrel for you, and re-crown it. You wouldn't be having the problems you are now having. I have never heard of filling off the barrel to get the gun to shoot where you want it too? Shotgun barrels are very easily bent, and most gun smiths use this fact to change the point of impact. Since you did the cutting, and there is no crown, then you might try filling. Please let us know how it works out!
     
  12. johnlives4christ

    johnlives4christ Former Guest

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    howdy carver, and everyone else. filing the end of the barrel did work, and it did move my point of impact. it didnt take very much either, only a few thousands of an inch. i had heard of this method from a now dead friend that was an avid shotgunner. he shot skeet, and trap and collected anything that threw shot. i asked him once about something along this lines and he said all you had to do was file the end of the barrel a tad to move the pattern. said he had heard of people bending the barrel a tad and didnt recommend it much. one thing that i didnt consider in the operation was the crown. but now that i think about it..... the choke tubes for most shotguns dont have a cut crown but only a square shoulder. atleast the ones i have seen, the gunsmith also told me that i could take a dowel rod with some 220 sandpaper and open up the chock very very slightly in the direction i wanted the pattern to move. although i didnt do this because it wasn't off much and he said filing it would work just fine.

    one reason that i didnt install the bead myself is because i dont have a tap for the treads. i did however, before i cut the existing bead/barrel end off, drill a new hole in the spot of my choice for the new bead. the reason being that it is a lot easier to get a bead centered on a barrel if you line it up with old bead instead of just the muzzle.

    after i cut and ground the end square, i took a file and some sandpaper and took the burr off the inside and outside of the barrel.

    since my pattern wasnt off much, and after some though i alluded to the fact that i could have ever so slightly been out of square, or given one side just a tad more "crown" .

    one thing that i havent considered until now is, that i never had patterned this gun before, so for all we know, it could have been twice as far off before i cut off the barrel.

    ~john