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Can 5.56 mags convert to 6.8 SPC?

SigfanSigfan Member Posts: 185 ✭✭✭
edited October 2007 in Ask the Experts
Can you convert 30 round 5.56 mags to 6.8 SPC? The SPC mags I see all say 25 round, and they are like $30.00 each. So converting 5.56 mags I already have would be a lot cheaper, if it would be reliable.

Comments

  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    Sigfan,

    Originally it was thought that the conversion to using the 6.8 SPC cartridge in 5.56 magazines was just to switch the follower and the spring. Unfortunately it's a little more complicated than that due to the increase in the diameter of the 6.8 case.

    http://ko-tonics.com/files/Mag-Feed-Lip-Tweak.pdf

    "Magazines for AR-15 and M16/M4 rifles were originally developed
    for the .223 Remington/5.56 NATO cartridge. For the 6.8 SPC
    cartridge, the magazine had to be modified to fit the wider 6.8 SPC
    case. Compared to a standard magazine, 6.8 SPC magazines
    have narrower ribs, and are made of stainless steel to resist
    deforming when filled.

    One part of the magazine that was not fully redesigned is the feed
    lips. For 6.8 SPC, it is necessary to "tweak" the feed lips to align
    the front of the cartridge for better feeding."

    Now, be assured that some of the cobblers will come along and tell you that they have the secret to convert 5.56 mags to use the 6.8 SPC cartridge. My point is that in order to assure consistent 100% feed and function, you need to have the 6.8 SPC magazines. I am aware that this causes some financial strain since you now have to have two separate types of magazines for the uppers you want to shoot. But failure to feed and function doesn't really do anyone any good does it?

    There is more information written on the internet so use a good search engine to locate the articles.

    Best.

    ADDED:

    Brownells sells a tool to assist with the feed lip adjustments.

    Best.
  • SigfanSigfan Member Posts: 185 ✭✭✭
    edited November -1
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