https://www.youtube.com/watch?v=u8nHo2_uL2k

Watched the above destruction test for a Slate Black Industries VFG alongside a Magpul MOE VFG; impressive performance on the Slate grip but as Henry says in the video, both rails got pretty badly mauled.

This made me wonder: although no one's really hitting vertical foregrips with a sledgehammer in real use, a hard bump like one from a sledgehammer seems very plausible if you're using the rifle harshly (e.g. pushing really really hard against a barrier, trip and fall on the rifle, drop it or generally knock it around). A vertical foregrip protruding so far out from a rifle seems like a plausible damage point in this way.

Has anyone experienced damage from a hard bump or drop on a vertical foregrip, that warped the handguard in the way that Henry depicts here?

Hitting a VFG w/ a sledgehammer (mini or not) isn't even remotely close to bumping into something, dropping the rifle, or pushing against a barrier.
Not to mention, if you plan to abuse your rifle or use it in a manner other than planking/target, buy parts that have been battle tested.

To answer you question, no, I've never seen anything like this on my personal rifles. I, however, never use VFG's.

What is the point?  If you give me a 20 ounce framing hammer I can beat the shit out of any protrusion.  Like the FP says, I don't use vertical grips.  And even if I did, I wouldn't hit them with a hammer just for shits and giggles.

Abusing something to make it fail is just dumb.

In the Henderson Defense threads, he said that customers were hard on the rails bc they were torqueing hard on the VFG, iirc.

On full auto guns, right? This is a business that caters to people with money that for the most, do not come from actual shooter experiences where they would properly know how to control the gun or at least have been taught to shoot using short controllable bursts, correct? If I was a high roller from japan with no pew pew time, I'd be holding on to that VFG with a death grip myself while mag dumping on the happy switch. Have it being done enough and over time its inevitable that stress fractures will occur.

Asides from that, I don't think anyone is going to be jamming their guns on any course of fire with as much force as those two demonstrated were being hammered with. Anything hit by a heavy mallet with enough weight to make most things bolted on to bend. Then there's the question of the integrity of the rails. Which ones was Henderson using or in the video, what make and was it Chinesium?

The video is a big meh. If the OP is that worried about it, may as well not get a FF tube either, what happens if he drops it with enough force like in the video and it bends?

I’ve seen rifles get straight thrashed on (regular and free float) without ill effect. The vertical foregrip will not damage your rail.

That's the dude from that one channel where he and that white dude test all the cool guns.

Right?

Um, this is how a lot of testing is done.  I'm not even isolating this statement to firearms - all kinds of industries.

Someone grabbed my M4 in Afghanistan, so I did a push-pull to break his grip then I bonked him on the chest/clavicle with the KAC VFG to knock him down. Meant to barrel thump him but the VFG hit instead.
Checked it out on the ride out and the tube had a fat crack. No discernible damage to the rail.
Now that I think about it, the KAC/P&S sticks being made out of plastic is probably what made the difference, compared to steel screws.

“So what happens if you take a vertical grip and whack it with a sledghammer”

It looks like a cheap Chinese mlok rail.

Besides that. I think personally I’d prefer that the $40 vertical grip fail before it bends the $400 rail.

I bent the bottom rail on a RIS II with a LaRue FUG.  

I slipped and crashed into a barricade at a match.