Bushmaster ORC: upgrade or trade?

Discussion in 'AR-15 Discussion' started by Shopfox, Feb 15, 2016.

  1. Shopfox

    Shopfox Active Member

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    It's a 16" flat-top with chopped off Front sight block, M4 profile, and chrome-lined, standard handguards. Accuracy is ok: about 1.75" 5-shot groups with American Eagle 50gr. Varmint tips.

    I want a lightweight rifle for walking, shooting coyotes, and shooting groundhogs, also some bench-top shooting. 200-250 yards would be my max hunting range. I have a RRA 2-stage varmint trigger, and a Weaver Super Slam 2-10x50. I want to keep and use these parts on this setup.

    I'm thinking about putting on a 7" free-float tube with a single stud, and changing the gas block to eliminate the dangling sling attachment.

    I'm hoping that I can get my group sizes down 1/4"-1/2" with the free-floating, and better rest (bi-pod). The main reason is a 3.5" pattern at 200 yards seems too big for groundhog shooting. Part of the group size could well be the 10x optics - maybe more X's = smaller groups...

    instead of spending $80 for a basic float tube/sling stud and $45 for a gas block, would I be better off selling my upper and buying something different?
     
    Last edited: Feb 15, 2016
  2. samnev

    samnev New Member

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    Yes, I doubt if you can get the ORC to shoot in the 1/4"-1/2" range.
     

  3. Shopfox

    Shopfox Active Member

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    I Worded it poorly, I want to get down to 1.25" to 1.5" groups. I'm close, but not there. Not sure if spending the money on the float tube will give me the nudge.
     
  4. Shopfox

    Shopfox Active Member

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    Case closed. I was having problems getting my groups tighter. I wasn't having much success. Through trial and error, on another rifle I found I could get better consistency and results by shooting with a bipod off bare earth vs a bipod on the bench. Applying this same lesson, I took the Lead Sled DFT off the benchtop, and used it from the prone position on the ground (The ORC doesn't have a sling stud to attach a bipod, so it had been difficult for me to get it really steady in the past).
    All 5-shot groups 100 yards:
    American Eagle 50gr: 0.817"
    Hornady TAP 55gr: 1.377"
    Hornady TAP 55gr: 1.271"
    Ave of Hornady: 1.324"

    Basically, I'm where I want to be for this rifle, and adding a free-float handguard will help me to add a bi-pod and reduce tensioning the barrel, making these numbers achievable without the Lead Sled.
     
    Last edited: Mar 3, 2016
  5. Shopfox

    Shopfox Active Member

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    Pics for my notebook...
     

    Attached Files:

  6. Shopfox

    Shopfox Active Member

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    Hornady group 1
     

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  7. Shopfox

    Shopfox Active Member

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    Hornady Group 2
     

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  8. Biohazard2

    Biohazard2 Active Member

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    What is the twist rate of your barrel?
    You may benefit by using heavier bullets such as 175 grain.
     
  9. fsted2a

    fsted2a Active Member

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    I'f you are good to go with removing a pinned gas block, I say go with installing the freefloat.
     
  10. Shopfox

    Shopfox Active Member

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    I ended up putting a carbine length Hogue free-float tube on w. bipod swivel ($60 installed). I reused my bastard gas block. I resighted it in off the bipod. 3 Groups ranged from 1-1/8" to 1-3/8". Accuracy is sufficient for my use.

    the lead sled can now be left at home.
     
  11. Shopfox

    Shopfox Active Member

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    Shot (3) 5-shot groups of American Eagle 50gr today:
    1.232"
    1.030"
    1.438
    Ave: 1.23"

    This matches with last session (about 1-1/4), so (5) 5-shot groups at 1.25" range seems solid.

    Originally it was shooting in the 1.75" range with the same ammo, so the improvement was about 0.5" after free floating the handguard.