Tweaking the mag for better accuracy

Discussion in 'Mini-14 Forum' started by tri70, May 8, 2012.

  1. tri70

    tri70 New Member

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    I have mentioned that I tweak my mags for better accuracy from my minis, I used a pair of channel lock pliers or lineman pliers to bend the front of the feed lips up slightly. My best shooting mags is a Promag 20, the steel is easier to bend, so don't give up on cheap mags. I have been working with some of my factory 20 and 5 rd mags to get them shooting better but it takes longer because they have stronger steel. The first picture is the tweaked mag showing the slight upward bend on the feed lip. The second picture is a stock mag for comparring. I bend both sides of the mags, the factory is tough to bend so be careful, it's easier to bend up but bending down is even tougher.
     

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  2. mountainman13

    mountainman13 New Member

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    How does altering the feed lips effect accuracy?
     

  3. rifleman1

    rifleman1 New Member

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    my thoughts excactly
     
  4. GReents

    GReents New Member

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    Some people are reporting a change in POI and group size from one magazine to another. Many report better accuracy with Ruger 20rd mags as opposed to the Ruger 5 round magazines. The thought is the spring tension and lip configuration play a roll in the amount of force on the undeside of the bolt causing some difference.

    With the 5 round magazines many report a consistent 3 and 2 pattern. Three shots grouped tightly and then another two offset and also fairly tight. Some people report just the first round off from the other four with the grouped four being very tight.

    One school of thought is the first round is stripped using just the manual retraction and release of the bolt. The rest being stripped by the gas system propelled movement of the bolt. And this causes a change in the flight path in some way.

    Tri70 has labeled each of his mags to track performance and has come up with these tweaks. He seems to have done the most extensive tracking.
     
  5. mountainman13

    mountainman13 New Member

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    Hmm first I've heard of it. Very interesting and when explained so well it does sound like a mechanical probability. Very cool.
     
  6. tri70

    tri70 New Member

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    I noticed this affect several years ago, I handload and no the ammo is accurate out of my bolt gun. I would load different mags with good ammo and get different groups and poi and that got me on this path.
     
  7. tri70

    tri70 New Member

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    I posted a target in the Reloading &ammunition forum under the Alliant Varmint powder. I got a good group with a 1 at shot flier and the next 4 printed close to 1" . This was done with my Primate 20 rd. My target mini will shoot almost 1" every time with this mag.
     
  8. TLuker

    TLuker Active Member

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    Ditto, that's cool. I have never thought about the magazine affecting accuracy. :cool:
     
  9. cl60cruzer

    cl60cruzer New Member

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    could alternating tension both vertically (reducing tension with firing) and laterally( staggered ammo) cause bolt to move around and cause case to move around in chamber? bolts have slop front to back as well as side to side. feed lips moves up hold constant tension on bottom of bolt
     
    Last edited: May 9, 2012
  10. tri70

    tri70 New Member

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    It is a floating bolt but you want the best angle and spring tension to be applied every shot. The factory mags have the best springs and will keep movement to a minimum once they are fixed.
     
  11. cl60cruzer

    cl60cruzer New Member

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    take the mag out of the equation and single load with no mag. push the right lug down with your thumb before every shot to make sure you are forward uniformly and shoot a group
     
  12. tri70

    tri70 New Member

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    Went out today with my target mini 14 and was working with a factory 20 rd mag, I have notice these are made of better steel than the aftermarket Promags and required a slight bend up on the back side of the feed lips as well to get the propper bolt pressure applied for best results. Here is a target from today. The top left is the factory 20 mag, the top right is my Promag 20 (only fire 4 shots) the middle is another factory mag I am working on. I was shooting off the ground and it was giving a bad mirrage affect at times. My brother was shooting his Savage 308 and at first it was shooting bad till he figured out the best time to shoot just after the breeze died down and less mirrage affect.
     

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  13. tri70

    tri70 New Member

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    The target was made from drawing circles around a quarter.
     
  14. jimogden1984

    jimogden1984 New Member

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    Do you think tweaking the mag a lil would have the same effect on the mini 30?
     
  15. Chainfire

    Chainfire Well-Known Member Supporter

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    You are going to have to work hard to convince me that when that bolt closes and the firing pin hits the round, that the magazine makes any difference in the point of impact.

    The only thing I have ever accomplished, monkeying with the feed lips, is buying new magazines.
     
  16. tri70

    tri70 New Member

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    It will help all minis, it has worked for my 6.8 too.
     
  17. tri70

    tri70 New Member

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    I understand, I was not having much luck with factory mags till today. Gave a slight tweak on the back of the feed lips.
     
  18. tri70

    tri70 New Member

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    Chainfire, do you still have a mag that was not shooting well? I would offer to fix it for you if that would convince you.