Kerm-Lock

Attached File


First of all, I really like the ease of attaching and detaching this mount, and the fact that it utilizes the old school OEM handguards.  I'm not really into metal rails and all manner of M-Lok, Keymod, Picatinny, and other ways of mounting lights, although I've tried them all.  I prefer KISS when it comes to mounting accessories, and this fits that bill nicely. It tends to position a flashlight better for hand reach with the fat M4 handguards, although it mounts just fine on the older skinny CAR handguards.

An online review

I really, really want to like this mount.  I just got it  yesterday so I haven't even gone to the range with it mounted yet.  I love it for positioning the flashlight in just the right position, though.

Some concerns:

1.  The instructions say to keep it away from chemicals that might damage the polyurethane doughnuts.  Okay.  That might be just boiler plate language.  How susceptible is polyurethane to damage from gun cleaners and lubes?

2.  My main concern is that the heat from firing might deteriorate the poly materials in the mount.  I am considering removing the mount entirely for range trips and just attaching it when it's at the house for home defense.

What do  you think?

Have you used these?

Have you "torture tested" them?

Based on the way it mounts I wouldn't trust it very long.  I don't like how it uses rubber donuts to "mash" and hold everything in.  The entire way it attaches is the single largest failure point.

I think I would prefer the IWC mount for the same role personally.   But, all the luck to the inventor and marketer of the mount being discussed.

I think I remember reading about that one some years ago, but I've forgotten the specs.  How does that one mount?

EDITED TO ADD:  Nevermind, I found it.

Mount-n-slot light mount

Same here, I would much prefer the screw on mounts. Even a 1911 rail mounted with an offset light mount.

I can see the product in the OPs post being good for a law enforcement officer whom is issue a new standard hand guard AR15 every shift and wants to add a light to it though.  Beyond that it seems to risky.

Edit:

This is to funny, what I said above is confirmed by their website.  Its actually why the guy made this and makes complete sense.  For anyone else there are better options out there.

For a while I ran this with a light mount.

The Kerm-Lock does seem like a product that you attach when you need it and remove it when you don't.  I would think repeatedly heating it  up in extended range sessions would deteriorate the polyurethane inserts pretty quickly.

Being the Kerm-Lock inventor, I'm happy to answer any questions. I welcome any feedback, positive or negative. I'll start by answering a few questions based on my research and development, years of use, and customer feedback.

Has it been torture tested? Yes. The polyurethane compound has a very high heat resistance, and it's shape memory is very good.

Why do the instructions state don't use chemicals on it? While the polyurethane compound is quite resistant to most chemicals, it's not 100% impervious. While most of us wouldn't think of soaking it in solvent, or lubing it up, somebody out there will. Some cleaning products have a lubricating component to them, which may render the holding mechanism ineffective. In short, it's language I just thought should be there.

As DocGlockster mentioned above: "The Kerm-Lock does seem like a product that you attach when you need it and remove it when you don't." Yes, exactly that. The Kerm-Lock was designed for rapid installation, searching and shooting in low light or darkness, then removing it. However, that being said, I will say it is amazing how well those polyurethane bushings hold when expanded. A lot lot lot of R&D went into creating the bushing assembly.

Okay, good info.

Given that some people who want to use an AR for home defense and might want to leave the flashlight on the weapon all the time, it's important to know if the device can take it.

Here's the $64,000 question:

In your instructions you say to store it in the relaxed position.  Is it therefore, not advisable to leave it attached to the handguards all the time?

That's true, and here's the reason: It's not about holding power while it's installed. It's about maintaining the bushing's integrity and memory for the next time you put it on. Much like a magazine spring, if you leave it in a relaxed state, it will probably last forever. If you leave the Kerm-Lock permanently installed, it will eventually diminish the bushing's memory over time, or at minimum, take a little time to return to original shape. Call it CYA instruction language if you like, but instructions need to try and cover every possible scenario a human can do with a product.

I designed and built this product with the following law enforcement mindset: This is a tool that needs to work right the first time, in the dark, under stress, without looking at it during installation, maybe while pulling up to a scene with a dozen things running through your mind, maybe while moving on foot. It's not a time to fuss with something. Therefore, it needs to be used and maintained in the best way that preserves it's intended operation and facilitates its rapid installation.  Everything wears out eventually, but "eventually" needs to be as long as possible, and not be a surprise when it happens.

Thanks for the honest answers.

If one wanted to leave the mount installed all the time, I think there is a work-around even if the polyurethane bushings go south.

Given that one does not need to dismount the Kerm-Lock in order to remove and reinstall the top half of the handguard set, I would think that one could install the Kerm-Lock as per the instructions, and before the bushings are compressed, one could go around them with a thick layer of heat resistant silicon or other adhesive. Then compress the bushings and apply more silicon to keep the polyurethane bushings "captive" even if they deteriorate.  Yes, it would mean that the handguard half in question is effectively permanently "converted" to a flashlight mount handguard, but so what?  You're trading the quick detach of the Kerm-Lock for the slightly less convenient need to dismount the entire handguard if necessary.  This would make it like a lot of law enforcement carbines that used the Surefire 500A handguard light for example.

What are your thoughts on this?

Anybody?