Ar15 accuracy upgrades

Discussion in 'General Rifle Discussion' started by ar4711, May 23, 2014.

  1. ar4711

    ar4711 New Member

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    I have a bushmaster xm15 patrol mans carbine and was wanting to get better accuracy out of it (223) I was wondering if anybody had any clues on how to get better accuracy out of it , it has the standard 16.5" barrel on it stock bolt also a ATN mk390 night optic on it very crisp clean rifle I was wondering if there was any quick and under about 200$ upgrades to get better accuracy and distance on it please and thankyou
     
  2. jjfuller1

    jjfuller1 New Member

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    change to a free floating handgaurd
     

  3. ar4711

    ar4711 New Member

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    Is that going to add much or ?
     
  4. jjfuller1

    jjfuller1 New Member

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    a little. not tons. also could change the trigger. but that doesnt mean its going to make your rifle more accurate, just means you will have a better trigger that with practice could make you and your rifle more accurate together.

    not sure of your skill set but most rifles will shoot better once the shooter becomes proficient with said rifle.
     
  5. ar4711

    ar4711 New Member

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    I am proficient with the rifle I can (not using night scopes) put on my Nikon scope and shoot 250yard 6" groups (not great but) all day long but I want to be able to make the 500+ shots though
     
  6. SSGN_Doc

    SSGN_Doc Well-Known Member

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    What kind of accuracy are you getting now?

    What kind of ammo are you using now? Having a load that YOUR rifle likes makes a big difference.

    Do you have a day optic? Being able to have a consistent aim point is important.

    How are you shooting it when you are judging the accuracy? (Standing, benched, prone, using a sling, a bipod?). Keeping pressure off the barrel is important.
     
  7. SSGN_Doc

    SSGN_Doc Well-Known Member

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    Well you just answered a couple of my questions while I was typing.:D
     
  8. ar4711

    ar4711 New Member

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    Bipod (bayonet lug) I am shooting hornady 75 grain bthp rounds and yes a Nikon 9-14 40 mm
     
  9. Franklin1995

    Franklin1995 New Member

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    What is your rate of twist? Isn't 75 a heavy grain for 223? Also, you might get better accuracy out of a 20" barrel (I believe it takes a 20" barrel to burn all the powder, correct me if I'm wrong.) I have no idea how much that would cost you though.

    Maybe you should just put the $200 into more ammo and keep on training, that might make the biggest difference of all. Goodluck, and let us know what you do
     
  10. SSGN_Doc

    SSGN_Doc Well-Known Member

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    So, as I was saying, barrel harmonics can play an important part in repeatable accuracy by allowing the barrel to vibrate the same for each shot. One of the worst effects on accuracy can come from putting pressure on the end of the barrel, and having that pressure change with each shot. A bipod at thatched to the bayonet lug will not be great for accuracy. If a shooter wants to use a bipod or a sling for stability it is best to have those attached to a free floating handguard. This allows the barrel to move freely and consistently for each shot.

    Also on heavy bullets and twist rate: most Bushmaster barrels will have a 1:9 twist. This means it will make the bullet make a complete rotation as it travels forward over a distance of 9 inches. This twist rate will usually stabilize .223 cal bullets up to a weight of 68gr. Some 1:9 twists will stabilize some manufacturers bullets up to a weight of 75 gr but it may be pushing the edge of stabilization. For bullets of 75 gr and heavier a 1:8 or 1:7 twist is better.

    The 16" barrel is capable of accuracy out to 500-600 yds, but you will not have optimal velocity for keeping heavy bullets stable. Also with the lower velocity you will experience more drop at 500 yds.

    F you want long range accuracy I would take the 200 bucks and save it. Then apply it to a separate upper half that is made with long range precision in mind. This way you have your carbine upper for quicker handling and shorter range shooting, and a precision upper for your longer range shots. A good 20" 1:8 twist match grade barreled upper with a floated handguard will make a big difference.
     
  11. FrontierTCB

    FrontierTCB Active Member

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    Agree with Doc. Experiment with some lighter grain ammo and look into a free float hand guard or at least a different attachment point for the bipod.


    Sent from a phone I can use to do my taxes, but can't make a damn call.
     
  12. clr8ter

    clr8ter New Member

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    A couple weeks ago I was looking at free float hand guards, and it seemed to me that they were all $200+++. Closer to 300, really.
     
  13. SSGN_Doc

    SSGN_Doc Well-Known Member

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    I have an older YHM free float handguard in one of my 16" carbines. It is not the most high-speed, low-drag handguard but is is cheaper than some and with the right loads I have been able to get 3-4 inch groups at 300 yds. I use this carbine as my coyote rig.
     
  14. clr8ter

    clr8ter New Member

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    Oh yeah, they have some from $71-$180 ish. Interesting.
     
  15. John_Deer

    John_Deer New Member

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    Get some ammo the gun likes. There is only so much you can do to a rifle. I have a DPMS with iron sights. I have no idea how far I am shooting but I can hit a golf ball as far as I can see it. I know I can hit a plastic baseball at 300 yards.
     
  16. Overkill0084

    Overkill0084 Active Member

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    The single biggest accuracy improvement I've had was finding a load the gun liked. Reloads mine (RRA) liked cut group sizes pretty much in half vs. decent, if not exceptional, factory ammo. Match grade ammo might be worth a look if you not willing to/unable to reload.
     
  17. JonM

    JonM Moderator

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    the patrolman is a good 2moa-3moa so 6 inches is inline with what your experincing. mechanical acuracy might be a bit better and in the hands of a very skilled shooter it might get closer to 2-3" when using tuned handloads.

    there really isnt much you can do to increase accuracy on a lower end production tifle for cheap.

    if you have the tools taking off the muzzle device removing the barrel from the reciever and retorquing the muzzle device to the proper value and doing the same for the barrel might clean things up and increase it a bit. these guns are usually overly loose or overly tight. as bushmaster isnt really interested in doing things right just shoving guns out the door.

    its similar to production bolt guns like savages winchesters fn's etc.

    for example... you would think that a scar17 would be put together well. mine was shooting around 1.5 moa which is pretty good. i took it apart retorqued everything correctly and evenly and i can get .5 -.25 inches at 100 most days
     
  18. ar4711

    ar4711 New Member

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    I have the tools to retorqe everything I will try this and I ordered a standard bipod for my rifle I also picked up a full picatiny rail system not free float but I'm ordering one soon and I will add these and see what I can get thanks for all the help everyone
     
  19. SSGN_Doc

    SSGN_Doc Well-Known Member

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    Shooting from sandbags is usually better for accuracy than a bipod. Try to cradle the handguard nearer to the receiver.
     
  20. ar4711

    ar4711 New Member

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    Thanks man