Do you have a .300 BLK and a .223?

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  • dudley0

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    99   0   0
    Mar 19, 2010
    3,725
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    Grant County
    Interesting pic. Having just started running a 300 blk I decided to use the few Pmags I have for that caliber. That is the only protection other than eyesight on the round that I have.

    I considered setting that upper with a color and the same with all the mags. Guess I could run tape on the mags to keep a fast swap out of the picture until then, but running metal mags on the 5.56 is working thus far.
     

    bulletsmith

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    11   0   0
    Apr 26, 2015
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    Lake County
    Wow, I have never tried to chamber a 300 round in a .223 receiver, I suppose that's an overall good thing. I had no idea that this could even happen though it makes sense. Good info, thanks!
     

    warthog

    Shooter
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    66   0   0
    Feb 12, 2013
    5,166
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    Vigo County
    since the round, 300ACC, is nothing more than a shortened 556/223 with a 308 bullet it is no surprise people are chambering the wrong caliber in the wrong firearm.

    My answer, PAY ATTENTION to what you are doing.
    15219478_1549529805060767_4456787948816751397_n.jpg
     

    JamesV

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    Dec 13, 2015
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    The Region
    Very good to know, I'm currently gathering items for my first ar-15 build and was thinking of my second to be a .300 next.
     

    88E30M50

    Grandmaster
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    12   0   0
    Dec 29, 2008
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    Greenwood, IN
    I guess if both of your weapons had identical setups I could see it being a concern.

    My 300BO pistol is very different than my other ARs, but this is still a concern. As long as I have 300BO loaded mags, this is something I need to be very aware of.
     

    halfmileharry

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    65   0   0
    Dec 2, 2010
    11,450
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    South of Indy
    I don't have a 300BO YET but have seriously considered building or buying one.
    This has never crossed my mind until now. I'm sure I'll keep this in mind now.
    Thanks for posting this. Good education
     

    shibumiseeker

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    49   0   0
    Nov 11, 2009
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    near Bedford on a whole lot of land.
    I suppose some people need the graphic to let them know the two can be cross-chambered, with the .223/5.56 generally not seating far enough to go into battery and the 300BO being able to chamber if the bullet profile and seating depth are short enough.

    I've shot both since the 300BO came out and built some redundant checks into my routine and don't see it as a big deal. I try to be very aware of everything gun related as I have seen firsthand what complacency or overconfidence can do.
     

    Gluemanz28

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    29   0   0
    Mar 4, 2013
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    Elkhart County
    I ordered some Mag Bands to put on loaded mags just because they look cool. I thought about getting some that say super or sub on them too. Maybe I should market some that could be flipped over to say super on one side and sub on the other.
     

    jblomenberg16

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    Mar 13, 2008
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    Southern Indiana
    We've been discussing at length on ARFCOM and I've run some of my own chambering tests. The picture above is the best/worst case scenario with a light bullet seated relatively short. Heavier bullets seated to mag length will typically not fully chamber, but after repeated attempts, or if the user uses the forward assist, they can create set back and cause the issue.

    I'm not saying its not an issue, but with some basic gun safety techniques and making sure to use the right ammo (which you should do on EVERY gun), the risks are really not that great.

    Yet ANOTHER .300 Blackout round fired through a 5.56 Barrel(pics of course) - AR15.COM
     

    EvilKidsMeal

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    14   0   0
    Feb 11, 2010
    1,719
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    Highland
    This is why I use different mags and have an engraved dust cover that says 300AAC Blackout on my pistol.

    It doesn't take much to look at a mag before you pop it in, but extra insurance is always good.
     

    ljk

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    May 21, 2013
    2,690
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    Lancer 20 round clear mags, baby!.

    I bought 15 of these when botach had it for $11 each shipped.

    Magpul windowed Pmags suck anyway.
     

    Ggreen

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    Sep 19, 2016
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    SouthEast
    I generally don't preload both 300 and 5.56 when I have both at the range. I also try to keep one in the case while the other is out and my 300 rarely goes on trips with other friends who are shooting 556 that day.
     
    Rating - 0%
    0   0   0
    Dec 11, 2012
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    01001111 01001000
    We've been discussing at length on ARFCOM and I've run some of my own chambering tests. The picture above is the best/worst case scenario with a light bullet seated relatively short. Heavier bullets seated to mag length will typically not fully chamber, but after repeated attempts, or if the user uses the forward assist, they can create set back and cause the issue.

    I'm not saying its not an issue, but with some basic gun safety techniques and making sure to use the right ammo (which you should do on EVERY gun), the risks are really not that great.

    Yet ANOTHER .300 Blackout round fired through a 5.56 Barrel(pics of course) - AR15.COM

    That's pretty crazy!
     
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