The M12 rack was developed for the M16 and M16A1 and still works fine for the M16A2 and M16A3.
The locking arms trap the carry handle and keep you from lifting the rifle clear of the recesses.
The M16A4, M4 and M4A1 are flat-top designs and can be maneuvered out of the rack without unlocking it.
Before:
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There's instructions in TM 9-1005-319-23&P (Nov08) to cut a piece of 1-1/2x1/8 angle iron so that it blocks the pistol grip and holds flat-tops captive in the rack.
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Like so.
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You drill it in place in the rack, remove it for painting, then bolt it in.
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There's hardly any tool clearance for the nut on the other side, so you're not removing it with the rack bolted to the wall. Also the bar is tight enough that you can't move it as long as the bolts protrude through the back of the rack. Actually a well thought out modification by our military.
And back in its home:
![]()
Inside a lockable closet as well. I need to strip out the walls and make the closet fire resistant too.
The locking arms trap the carry handle and keep you from lifting the rifle clear of the recesses.
The M16A4, M4 and M4A1 are flat-top designs and can be maneuvered out of the rack without unlocking it.
Before:
There's instructions in TM 9-1005-319-23&P (Nov08) to cut a piece of 1-1/2x1/8 angle iron so that it blocks the pistol grip and holds flat-tops captive in the rack.
You drill it in place in the rack, remove it for painting, then bolt it in.
There's hardly any tool clearance for the nut on the other side, so you're not removing it with the rack bolted to the wall. Also the bar is tight enough that you can't move it as long as the bolts protrude through the back of the rack. Actually a well thought out modification by our military.
And back in its home:
Inside a lockable closet as well. I need to strip out the walls and make the closet fire resistant too.