Hello,

A friend of mine bought an Armasight Sirius SD. He already has a Protect Bravo helmet. He wants to mount his unit to his helmet similar to mine. I have a PVS-14 mounted with j-arm and rhino nvg mount. However, the Sirius is proprietary, if I am not mistaken, and won't work with standard PVS-14 mounts. Armasight says he has to use this:

http://www.nightvisionguys.com/armasight-helmet-mount-for-nyx14-night-vision-monocular

He is trying to avoid using a strap and save $ using his existing rhino and j-arm that he has laying around. Has anyone modded a mount for a Sirius SD without using the proprietary mount? (other than duct tape :))

Any help is appreciated?

One of my friends purchased an Armasight Spark. The recommended adapter was the #37. He could never get it to work right. I removed one of his rail panels and threaded the hole that it already had to 1/4-20 and filed a hair off of one of the edges. Presto: Now it's compatible with a PVS-14 J-Arm.

I assume you should be able to do something similar with the Sirius. The total cost to outfit him with USGI mounting was less money than the proprietary gear and by far outperformed it - of course we violated the warranty, but that was less of a concern for him than functionality.

Make sure you use one of the new J-Arms with square index pins or chamfer the index holes if the J-Arm is the old type with round index pins. Any time you are running a modded system like this you tend to put unforeseen stresses on the system and the J-Arm will likely lose its index.

Is there a way to work with it, without exactly modifying it as such?

I don't think so. I had a Spark too and it didn't play well with other mounting solutions.

I haven't looked in a while but there are some good videos on YouTube from guys who've modified the Spark to helmet mount.

So you might get some ideas from them IR you might be able to find similar videos for the Sirius

Here is a link to said video. Also check the recommendations below it. They are always videos on adapting the Spark to a helmet which might help you out.

Link to YouTube video

The #37 adapter did not allow Left/Right adjustment that my friend needed. This is all dependent on the placement of your eyes inside your skull and the size/shape of your head. It works for some people without any issues.

The #37 lets you adapt to USGI mounts without modification. If you go this route then I recommend the newer RHNO II (Norotos Titanium Lowering Arm) because it has vertical adjustment that the old RHNO Lowering Arm lacks. Depending on the shape of your head you may be able to rotate the helmet to get some Left/Right adjustment. My friend is of solid German ancestry and he has flat sides to his head so we could not get much rotational adjustment from the helmet. If you have a rounder head this may work better for you.

I have seen THIS done without modification to the MNVD (Monocular Night Vision Device - Sirius, PVS-14, etc.)  though I have not done it myself: MNVD rail to Picatinny weapon mount adapter, Picatinny adapter to Picatinny rail, Picatinny rail to offset bracket, offset bracket to Wilcox Dovetail - at which point the Wilcox Dovetail will mate to any Wilcox Lowering Arm. This sounds like a lot of work and Wilcox Arms do not come cheap.

If I really needed to do this without violating the warranty then I would get one of the $25 aftermarket weapon mounts off of eBay and get the USGI J-Arm mounted to a piece of Pic rail. I think that would be less work.

Tapping the proprietary rail was easy and, if you are out of warranty anyways, that is definitely what I would recommend. Cheap, easy, decent results.

EDIT: Post edited for clarity on request through PM.