I don't weapons mount 14s any more ... not saying I wouldn't in an "emergency" ... but ... not worth the risk to me ... I run them on my head or with a lanyard around my neck.
Back when I did ... I mostly ran it on a .22lr(16) (stoner work alike) for ratting ... but I ran it at least once on a 5.56(14.5) per this pic.
Note the 3x magnifier screwed on the front of the 14.
One advantage of running it behind the EOTECH is that the EOTECH let's more light pass through than other options. That said, I don't have that EOTECH any more as mine was one of the ones that got a fragmented dulled out dot, due to my using it in too many ice storms. Apparently EOTECHs didn't like ice storms. Who knew !?
Where 14s are very useful on the rifles/carbines is for co-witnessing tasks. And for that I got a Night Optics day/night adapter
http://www.nightoptics.com/product/NM-DN2.htm
Here is a setup for co-witnessing the laser in the radius to align it with the reticle in the day scope.
All co-witness tasks are so much easier with that day/night critter.
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If you really want to weapons mount, there exist "WG" (weapons grade) tubes, that might hold up a little better under recoil, and we could point you at a guy that can build you a 14 with a WG tube.
But the other way to weaponize a 14 is to put an ir-laser on your rifle/carbine. See with the 14 on your head, aim with the laser. Here is my current setup for doing that.