Yeah do not recommend.

just as recoil sensitive

Still not recommended.

Guys, here's what it gets down to:

The PVS-14 does not have any recoil or shock mitigation built into it the way a weapon-mounted optic does.

The fact that it's generally capable of surviving being mounted to a 5.56/.223 is more a testament to how mild the recoil is for those weapons, but even mounted on such a weapon, we do not recommend doing so too much or too often, as eventually the device will have simply had enough.

The fact of the matter is that a weapon with a weapon-mounted PVS-14 generally tends not to be a high round count weapon under most circumstances, because people are typically using weapons in this manner in a more static position, coyote/hog hunting, etc.

The TNVC TM-14 mount is, in some ways a "legacy" accessory.  

TNVC and then-Laser Devices (LDI, now Steiner eOptics) partnered back in 2011 to bring the first Class I IR lasers to the commercial market for wide sales and distribution, prior to that, firing solutions for NV were few and far between, with your choices often being gray market IR lasers or weapon mounting of a PVS-14.

The TM-14 was developed as a better option than the USGI Weapon Mount that could also double as a mount for the Aimpoint 3x Magnifier, which again, at the time was really the only decent RDS magnifier available on the market.

The TM-14 is still sold and still in production, as it has become a fairly popular product, however, unlike ten years ago, there are many more options for aiming with NV that are less risky and more practical in almost every way than weapon mounting a PVS-14.

Just because you can doesn't mean you should.

And even though you can, I wouldn't do it much.

If you have access to a machine gun, transferable or not, I've got to believe that you have the means to at least get a hold of a lower-cost IR laser at least.

~Augee

I don't know of anyone with much recognized credibility having done significant testing with 300BLK.

300BLK is "new" enough that it came about at a time when "weapon rating" for PVS-14s was no longer really a thing--again, before the advent of commercial Class 1 lasers designed for the commercial market (the PAQ-4C was Class 1, but never intended for the commercial market) it was a matter of greater concern, but by the time 300BLK really became "popular" and saturated the market, it was a non-issue.  

I generally tell people the same thing as with 5.56--you can probably do so safely sparingly, but I wouldn't make a habit of it.

~Augee

No

Are you talking belt fed? (I was imagining that you just meant like a RR M16 or something) If that's the case, then I would definitely say that an IR laser would be the better option, and not just for durability reasons.

Ultimately the smoke and dirt/dust and flash is going to be unavoidable, especially off a bipod with an MG, but it will be worse at the 12 o'clock tight to the weapon on the feed tray cover rail.

Passive aiming is not impossible, especially with binos, but again, somewhat less than ideal.

You're best bet is an IR laser, probably side-mounted, set to aiming laser-only (no illuminator), and trying to get behind the weapon in kind of an "upward facing dog" position looking up over the top of the weapon as much as possible. Depending on ROF/looseness of dirt/etc., the laser should still be able to punch through all the dust and smoke, and looking offset from it should allow you to look further downrange at where the laser is landing versus looking at the splashback through the haze, an AG/spotter is definitely very helpful as well.

If you are referring to an RR of some sort, I would say to try some taller mounts, which would make passive aiming much easier in the prone (as in every other position).

~Augee