What calibers can be used with the 556 lower?

Discussion in 'AR Talk' started by Plumberdude, Oct 18, 2008.

  1. Plumberdude

    Plumberdude XDTalk 100 Member

    Joined:
    Feb 7, 2008
    Messages:
    229
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Central Virginia
    Ratings:
    +0 / 0
    as the title says how many different calibers uppers can use the 556 lower. just wondering what my options are.
     
  2. GHILLIE

    GHILLIE XDTalk 100 Member

    Joined:
    Jun 14, 2007
    Messages:
    151
    Likes Received:
    2
    Trophy Points:
    0
    Location:
    East Central IL
    Ratings:
    +2 / 0
    .22lr, .223/5.56, 6.5, 6.8, .450 Bushy, 9mm, .40, 10mm, .45, 5.45x39, 7.62x39, 50 Beowulf, just to name the common ones. I'm sure someone will be along shortly to add more, like the .458 Socom, etc.
     
  3. Polymerhead

    Polymerhead XDTalk 2K Member

    Joined:
    May 2, 2005
    Messages:
    2,620
    Likes Received:
    3
    Trophy Points:
    0
    Location:
    MO, USA
    Ratings:
    +3 / 0
    You mean the AR lower, right? Not the SIG 556?

    Ghillie's right - just about any caliber that fits the mag well, and some that don't. You can get a 50 BMG bolt-action upper for your AR lower if you want. Or you could go all the way down to 5.7 FN, where the mag well becomes the ejection port! .204 Ruger is a pretty common one...
     
  4. GHILLIE

    GHILLIE XDTalk 100 Member

    Joined:
    Jun 14, 2007
    Messages:
    151
    Likes Received:
    2
    Trophy Points:
    0
    Location:
    East Central IL
    Ratings:
    +2 / 0
    .204.....I knew there was a popular one I was forgetting. :D I was distracted by the fact that the Illini football team was actually dominating the game for once. :mrgreen:
     
  5. Polymerhead

    Polymerhead XDTalk 2K Member

    Joined:
    May 2, 2005
    Messages:
    2,620
    Likes Received:
    3
    Trophy Points:
    0
    Location:
    MO, USA
    Ratings:
    +3 / 0
    Better than Mizzou this evening. A rough night for sure.
     
  6. ORD

    ORD XDTalk 1K Member

    Joined:
    Aug 15, 2008
    Messages:
    1,354
    Likes Received:
    6
    Trophy Points:
    0
    Location:
    West Virginia
    Ratings:
    +6 / 0
    Huh...you might ask what your options are NOT. Here goes (remember some of these are serious wildcat cartridges you won't find in your average AR parts/accessories catalog, but they work 100% in standard AR-15 lowers):

    17HMR
    .17Mach2
    .22lr
    .222 Remington
    .25 WSSM
    .204 Ruger
    6.5 Grendel
    7.62x39
    5.56x42(SPC)cat
    6x41(SPC)cat
    6mmBanshee(Grendel cat)
    6.5 Banshee(Grendel cat)
    6.8SPC
    6mmWOA
    6mm Hagar
    6mmAR
    6mmAR turbo
    458 socom
    50 beowolf
    338 spector
    30HRT
    300 Whisper
    6mm/223
    25/223
    30/223
    10mm
    45acp
    9mm
    40 S&W
    6BR
    6BRX
    6mmPPC
    223WSSM
    243WSSM
    25WSSM
    358WSSM
    (.50 BMG, .50 DTC, 408 Chey Tac, 338 Lapua Mag - for conversion uppers not using the AR-15's mag well...may require modification to fire control components, etc.)
     
  7. Plumberdude

    Plumberdude XDTalk 100 Member

    Joined:
    Feb 7, 2008
    Messages:
    229
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Central Virginia
    Ratings:
    +0 / 0
    wow lots to choose from. the 6.5 grendel upper is about 500 bucks from centerfire i was thinking of getting that for deer hunting. was just wondering if my stock lower would work. thx for the info
     
  8. ORD

    ORD XDTalk 1K Member

    Joined:
    Aug 15, 2008
    Messages:
    1,354
    Likes Received:
    6
    Trophy Points:
    0
    Location:
    West Virginia
    Ratings:
    +6 / 0
    The Grendel rifles are VERY nice and the 6.5mm round is just a wicked little bugger...especially with the 123gr Lapua Scenar loads out of at least an 18" barrel!! There is a great site dedicated to the 6.5 Grendel with tons of excellent information. If you have not happened upon it yet...check it out:

    6.5 Grendel Fan Site :: For the 6.5 Grendel Aficionado

    Also, Alexander Arms and several other sites have a lot of great information.
     
  9. Sharkbait

    Sharkbait XDTalk 500 Member

    Joined:
    Feb 28, 2005
    Messages:
    568
    Likes Received:
    2
    Trophy Points:
    0
    Ratings:
    +2 / 0
    Any reloading manual will have cartridge dimensions for the .223/5.56x45. Any round with an overall length equal to or less than the .223/5.56x45 will be able to use the existing magwell. My personal favorite is the .300 Whisper, the Whisper uses .223 brass cut off near the shoulder and necked down (doable with about $100 worth of reloading equipment) to .30 caliber and firing the .308 bullet. You can load 240 grain .308 bullets subsonic or supersonic. Similar ballistic performance to 7.62x39 but if you spend the money on a .308 supressor and load subsonic the rounds are VERY quiet! The ONLY part on a .300 Whisper upper reciever that is different from a standard AR15/M16 is the .30 caliber barrell, you can use your standard AR magazines and the boltface is the same so parts are readily available (brass, bullets, reciever and BCG)

    The 6.5 Grendel is also attractive because it uses many parts in common with the AR15/M16 and with a drastically higher ballistic coefficient the 6.5 Grendel is flatter shooting than the .308 and has more kinetic energy so out past 5-600 yards the 6.5 Grendel hits harder.
     
  10. Sharkbait

    Sharkbait XDTalk 500 Member

    Joined:
    Feb 28, 2005
    Messages:
    568
    Likes Received:
    2
    Trophy Points:
    0
    Ratings:
    +2 / 0

Share This Page

Search tags for this page

308 upper on 5 56 lower

,
can 556 ar lower be used with 300 blackout
,
can i put a 300 blk upper on sig 556
,
can i use my regular ar 15 lower with a 308 or 300 aac upper
,
can the upper of a 7.62 ar mount on the lower of a 5.56
,

can you use a 5.56 lower with a 308 upper

,

how many calibers can be built on same lower

,

how many calibers on ar15 lower

,

what caliber uppers fit 5.56 lower

,
what calibers can u make in an ar 15
,
what calibers can you use on a 223 lower
,
what upper cal can i put on a 223 lower
,
what upper can i buy to put in my 223/556 lower
,
what upper will go on a 223 lower
,
what uppers can go on a ar15 lower
,
will 300 will a 6.8 upper fit a 5.56 lower
,

will 6.5 grendel work 5.56 lower

,

will 6.8 upper fit on 556 lower

,
will a 300 blackout upper fit 5.56 lower
,
will a 5.56 fit a .308 upper?