Streamlight ProTac Rail Mount HL-X: Initial Impressions

As I have mentioned in previous articles development in tactical light technology is very much analogous to innovation in other technology industries such cell phones or computers. You might buy a light today and a few months from now find out the state of the art is significantly better than what you just purchased. In my case a considerable amount of time had marched on since I updated the weapon mounted light on my favorite 14.5’” AR. Since this gun wasn’t dedicated for duty or home defense, there wasn’t a ton of impetus for me to invest in a new light, that is until an excellent low light training opportunity popped up. Not wanting to show up running a virtually antique 300 lumen light I figured it was time to get up to date. Having been impressed with both the performance and cost-effectiveness of some other Streamlight products I have purchased in the last few years I decided to give the ProTac Rail Mount HL-X weapon mounted light a try.

The full specs on the HL-X can be had on Streamlight’s website (https://www.streamlight.com/en/products/detail/index/protac-rail-mount-hl-x), but the quick and dirty is that it is mountable to any Picatinny/1913 style rail, produces 1000 lumens, and has a retail price of less than $120. The light also has high, low, and strobe output modes that are programmable with Streamlight’s excellent Ten-Tap system.

My first impression of this light when I took it out of the packaging is that it was a bit bigger than I expected and very robust. It is significantly larger than either the Generation one InForce WML that I had been using or the Surefire Scout lights I have used in the past. This wasn’t necessarily a big deal but because of the large thumb screw used on the lights rail clamp it just wasn’t going to fit on the Hailey Strategic Thorn Tail mount I was already using. One area that I think Streamlight can improve upon with this light is making the whole rail clamp reversible to offer the user some flexibility as to how the light is oriented on the gun.

In the past my go-to location for a light has been at about the 11 o’clock position on the handguard as far forward as possible, this allowed me to activate the tail switch of the light with my left hand simply by turning my thumb a bit outboard. In those rare instances where I need to switch shoulders and shoot from my left-side I could also reach over the rail with my right thumb to activate the light.

One of the main reasons I set my light up this way is to avoid having to use a pressure switch (a.k.a tape switch). Historically tape switches attached to the gun with adhesives that melted when the gun gets hot causing the switch to fall off. They also didn’t offer a constant on function which I prefer on any hand held or weapon mounted light. For those using secondary IR lights, lasers, or IR designators avoiding the tape switch on the primary white light also offered additional real estate and options for the switching associated with those devices. My final beef with tape switches is that if they are improperly placed, they can be inadvertently activated (known as a white light ND) and give away your position while approaching a target.

Because of the non-reversible rail clamp and oversized thumb screw it was readily apparent that the HD-X just wasn’t going to work with an offset mount at my preferred 11 o’clock position. To rectify the problem, I set the mount up on the opposite side of the handguard and attached the light at the 1 o’clock. Much to my initial displeasure this necessitated the use of the included pressure pad. Thankfully like light technology itself pressure pads have come a long way in the last ten years or so. The one included with the HL-X has a long pressure pad on one end and a smaller raised button on the opposite end that activates the constant on function. Streamlight was also nice enough to include several mounting options for the pressure pad including a pre-cut section of high-quality 3M double side adhesive, several sizes of zip ties, screws, and a set of retaining clips that can be used to attach the pad to a rail. I was able to slide the pressure pad between two rail sections at 11 o’clock on my rifle and for some added security used the included double-sided tape (it should be noted I still wouldn’t use the double-sided tape as the sole means of securing the switch). In this position the pressure switch was easily assessible to my left thumb from my usual C-clamp grip and I was also able to reach it with my right thumb when shooting from my support side. With the pressure switch located between the two rails it was also protected from being inadvertently activated during normal carry or firing.

After getting the light mounted, I cleared my house a few times with it (after triple checking the rifle was unloaded and making sure nobody else was home). It didn’t take long to figure out that the strobe function on this light doesn’t work well for CQB (Close Quarters Battle). Room clearing requires that you are on and off of the light’s pressure switch a lot, often in rapid succession. The default setting for the light is that two quick taps activate the strobe mode. Consequently, I found myself inadvertently activating the strobe, not a good result when you are looking for bad guys in a structure. I think the utility of strobe mode on a weapon mounted light is dubious anyway, so a few minutes with the Ten Tap programming and I was able to switch my HL-X over to “high only” mode. This is something I would recommend everyone buying this light do unless you are really sold on having a strobe feature and train with it accordingly.

Over the weekend I had the opportunity to use this light set-up at Pew Pew Solutions Low Light Practice at The Farm in Fairfield Utah. The event was set up as a collection of different drill stations that were conducted at night using only white light. This gave me a good opportunity to test the HL-X out and I have to say I was very impressed with it. The switching was very intuitive and the position of the pressure pad was such that I had no issues with white light NDs. On one drill in particular I was able to easily find, identify, and engage, reduced torso size steel at 100 yards without issue. On closer targets the light was very bright, in fact on a white background it was washing out the lower settings on my Aimpoint T-1 red dot. If you are clearing houses with this light make sure you adjust your red dot setting appropriately. I did note that during the course that several other shooters using Streamlight ProTac series weapon mounted lights that were clearly having the same issues with the strobe mode that I had experienced.

In summary, I think this is a great light for the money. It has a lot of premium features that you typically only find with more expensive lights. My only suggestions, barring any issues that develop with continued used, is that Streamlight re-engineer the rail clamp to make it reversible or at least less obtrusive. They should also strongly consider changing the activation of the strobe mode to something that is less likely to be activated accidentally, as I said thought this is very easily rectified by the user. Despite those minor criticisms, I think this light is perfectly adequate for home defense or duty use, particularly if you happen to be on a budget.