6.8 to 5.56 Conversion

Discussion in 'Black Rifle Forum' started by Beware Owner, Oct 2, 2012.

  1. Beware Owner

    Beware Owner NOT a victim.

    What do you guys recommend as far as the BCG and bbl? I'm not going to swap out the whole upper unles it'd cost about the same to change the internals. I know to go with PMAGS...

    Wanna kill these ads? We can help!
  2. If you're not looking to spend a ton Palmetto is a good place to start. If you can spend a little more, BCM is where it's at. If it were me, I'd probably get Palmetto barrel and a BCM BCG.

  3. Beware Owner

    Beware Owner NOT a victim.

    I'm not too sure about the twist rate, is 1:7 the most common? Is it used for the heavier bullets?
  4. Big Bird

    Big Bird NRA Life Member

    A stripped PSA or Spikes barrel (both are FN) will run about $160-200 depending on your flavor. 1-7 is standard USGI twist but there are some advantages with 1-8 and 1-9 especially if you run a lot of 55 grain M193. If you want a barrel with a FSB you'll need to add about $50 to that price.

    All you need is a new bolt not an entire BCG. So about $60 for the bolt.

    And someone to screw the barrel on for you...
  5. 1 in 7 will be good for anything from about 50 grain on up. Some of the lighter constructed bullets may come apart out of a fast barrel like that, but I've never had an issue with any of the 55gr stuff I've shot. Accuracy may or may not be as good with the lighter bullets as with heavier, as well.
  6. Oh, and FYI, P-Mags are great but the problems with quality GI mags are greatly exaggerated.
  7. Beware Owner

    Beware Owner NOT a victim.

    Seems like you can't find a goog upper for under $700!
  8. Sure you can, depending on what you want. What features are you looking for?
  9. DougW

    DougW Native Texan

    I just converted one of my rifles from 5.56 to 6.8 with a Palmetto barrel and DPMS bolt. Barrel changes are easy for me because I have the proper tools, so the total conversion took less than 30 minutes.

    Pmags are great. I have 2 kids deployed right now in Kandahar using Pmags daily. But, there are a lot of good mags out there.

    1 in 7 is what the .mil uses. Good up to 62gr, possibly (depending on your barrel) 68gr. All my 5.56 rifles are 1 in 9.
    #9 DougW, Oct 2, 2012
    Last edited: Oct 2, 2012
  10. 1 in 7 is fine for up to 80gr or greater, generally.
  11. Beware Owner

    Beware Owner NOT a victim.

    Flip up front sight, M4 configuration, removable handle. Wouldn't mind a free floater, but that is what racks up the price, I think.

    I want to shoot both calibers frequently, looks like getting a dedicated upper is the best solution, would you think?

    Would 1 in 9 not be good for lighter loads?
  12. Big Bird

    Big Bird NRA Life Member

    Dedicated upper would be my choice and just swap out bolt heads. You can buy Stag uppers less a bolt carrier for around $480 and they are fine.
  13. The faster the twist the heavier the bullet it will support in .223. A 1-9 will work with around 69-75 grain bullets, but the 1-7 will work up to 80 grains and above. The 1-9 works well with the 55 grain rounds as well as the heavier 69 grains(some barrels will shoot 75 grains some won't, the 1-7 will shoot 75 grains but the 55 grainers aren't as accurate).

    If you don't have the tools on hand to do a barrel change, which includes a torque wrench, vise, clamp system, and barrel nut wrench you'd be better off with the second upper.
    #13 m2hmghb, Oct 2, 2012
    Last edited: Oct 2, 2012
  14. 1 in 9 would be fine for lighter loads, so long as you realize it limits you more than likely to 69gr and under. If you have no intention of ever shooting heavier bullets then don't worry about it. If you want to shoot both calibers frequently, another upper is definitely the way to go. Check out Palmetto State Armory under barreled upper assemblies section. You should be able to get what you want in a basic upper for south of $500, with the possible exception of the folding front sight as most of their uppers (and most of anyone's uppers) come with forged front sight bases.
  15. Beware Owner

    Beware Owner NOT a victim.

    Not bad! I'll definitely look into that.

    What do you prefer and why?

    I just saw that, nothing quick about just changing the barrel. Ugh.
  16. Beware Owner

    Beware Owner NOT a victim.

    What are your preferred twist rates and bullet weights?
  17. I like 1 in 7 because I shoot anything from 55gr to 77gr. I practice mostly with 55gr and don't have issues with accuracy serious enough to make me wish I had a slower twist barrel.
  18. I like 1-9, I don't shoot 77 grain rounds and most of the practice fodder is M193(55 grain FMJ) or 69 grain match rounds. Then you get into the chrome lined or not lined debate.
  19. You should definitely get a dedicate upper if you are going to be swapping frequently.
  20. faawrenchbndr

    faawrenchbndr DirtyThirty fan

    Would be better off ordering an entire upper

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