PDA

View Full Version : Rosch Works SLM2 (Surefire Executive) Front Sight//Light Mount Review



TehLlama
24 February 2015, 10:44
Rosch Works SLM2 and Surefire KM1 LED Head: Does this setup do it all?

http://i60.tinypic.com/rcploi.jpg

When I first encountered the Rosch Works SL1 line of integrated weaponlight//front sight setups, I was very curious to see if I had finally found the lightweight and affordable solution I had been seeking for my compact handguard carbines.

On lightweight rails the majority of default real estate is available on the 12:00 top side (e.g. BCM KMR, KAC URX-3/3.1/URX-4, Troy TRX/Alpha, DD V11 and V7 MFR, Centurion CMR, and the list goes on). When it comes to making efficient use of that space while keeping the complete weapon system svelte, the Rosch Works options are arguably the best possible solution, which is why it's unsurprising to me that guys like Mike Pannone have been running the Rosch Works offerings for over a year now http://www.defensereview.com/rosch-works-rw-sl1-sight-light-review-making-the-most-of-your-ar-15m4m4a1-carbinesbrs-tactical-real-estate/.

To further understand why the SL1 concept was so intriguing to me, I'll explain a bit about my weapon mounted light and irons sights preference I bring to this review. My preferred setup is influenced very heavily by Larry Vickers and others who prefer the ambidextrous and rugged capability of Surefire (or similar) weaponlights mounted at 12:00 in conjunction with fixed iron sights or a fixed front sight post - for example the X300/X300U from Surefire mounted in front of a fixed front sight post or Daniel Defense 1.5 Fixed rail mounted front sight. For me this arrangement confers all the advantages of a constantly cowitnessed fixed front sight which also serves as an accidental light discharge mitigating tool for the X300 light mounted on the rail directly in front; my wife has adopted this exact setup for her pair of lightweight carbines and really prefers this arrangement.

On carbines I own with low powered variable optics, I wanted to retain that same inherently ambidextrous 12:00 mounting solution, but with the ability to run folding and/or offset iron sights. Furthermore, I have discovered through extensive experimentation that my preferred activation solution for weapon mounted lights is the Surefire Z68 tailcap (as used in the Surefire Scout series lights). Again, the ability to press briefly and receive momentary light or push-through and have constant-on is quite desirable for me, and I prefer not to rely on remote switches if possible; so I've adopted running Surefire M300 and X600 scout lights, or VTAC L4 scout-like facsimile lights on non-offset aftermarket mounts at 12:00 as my answer for these rifles.
This does create some odd choices for location of backup iron sights - less problematic on my 16" Recce and 18" SPR setups that use the KAC offset iron sights, but on my primary training and general use carbine (a DD V5LW upper with Trijicon TR24RT 1-4x optic) I've found I have to run the MagPul MBUS roughly halfway down the rail and run my thumb in front of that folding sight to activate the light - not an issue as this setup works extremely well for me, and allows me to run a DBAL I2 nestled under the LT-135 mount, but it does give up a considerable amount of sight radius (effectively carbine length gas FSP location despite having a 12" OmegaX handguard).

http://i62.tinypic.com/4uyixt.jpg

For even shorter handguards I was presented with a problem in the form of wanting to still run a 12:00 weapon mounted light with fixed iron sights and run this setup in front of a LDI DBAL-I2 also mounted at 12:00. This created a pressing need for a weaponlight that was not only compact, but allowed for a fixed front sight arrangement (to be used with a micro Aimpoint). For what I wanted, the SL1 was almost the answer I wanted, but the SLM2 fits the niche as a truly ideal solution


For the initial SL1 design, the benefits were undeniable: the very compact front-to-rear footprint possible with this setup was clearly desirable on shorter handguards, especially applications like my 8" URX3 equipped SBR, with a huge added bonus being the impressive weight savings. For these reasons alone, the SL1 is a truly remarkable light in it's own right. If I was seeking a very affordable solution to a simple white LED WML and sight post space saver on a compact and/or lightweight carbine, I would be extremely happy with the existing SL1 (my complaints would likely be only related to the particular tailcap used on the Malkoff Devices light chosen for the SL1, although it appears Rosch Works is even working on a Z68 and SR07 friendly Surefire Executive tailcap adapter for the SL1 line to remove even this minor complaint).


When I first went through this logical process, I contacted Don at Rosch Works, and asked if it was possible to perform a slight modification to the inside diameter of the existing SL1/SLM1 design to accommodate the Surefire Executive series of lights. What I specifically had in mind was running the exquisite Viking Tactics L4 Surefire lights (basically an E2D/E1B tube, Z68 Tailcap, and KX2/KX1 LED Scout Head in a bargain package). The initial answer was that of course it was possible, but Don immediately pointed out that I'd be basically crazy for wanting to do that, since the SL1 already does everything that light setup does with a higher output (250+ lumen torch) and lower cost; but they'd start looking into trying to make the SLM2 (for Surefire executive series lights) setup anyway since it would allow use of the RoschWorks-SL1 light and IR laser systems using existing remote switches like the Surefire SR-07-D-IT without requiring a tailcap adapter.

Once I got the go-ahead from Rosch that the SLM2 was a real possibility, I realized that I wanted something one step further: a White/IR capable weapon mounted light with integral front sight - even though this line of thinking was back in May 2014, I had a good enough understanding of Surefire product development timelines to make a reasonable assumption that eventually a KM1 LED Head (3V White/IR Scout Light Head from the then unannounced M300V Scout Light) would come out, and allow me to take a Surefire 3V Executive (E-1) body, install a Z68 Tailcap, and KM1 head and have myself a poor man's M300V - an option not immediately available from Malkoff Devices.

This means that a Rosch SLM2 with the KM1-Vampire LED head becomes a truly one-of-a-kind triple threat bolt on part: a fixed front sight which houses a white/IR weaponlight. Not only is it the most compact and lightweight setup possible, the total price comes in well under $500 for a complete unit. In price comparison terms, a VTAC L4-Mini, Rosch SLM2, Surefire KM1-LED (which leaves a bonus leftover KX1A head) once completed competes directly with the much larger, heavier, and pricier M720V RAID White/IR system... which is too tall to be mounted at 12:00 and still lacks a front sight requiring even more cost.

http://i61.tinypic.com/142sso8.jpg


Feel, Fit, and Finish

Having received a pre-production model of the SLM2, I can't comment on the final packaging, but the remainder of the delivered setup is really quite attractive. The machine work is excellent, and on the three handguards I've mounted it on (KAC URX-3.1, DD RIS-II, and DD Omega-X) the SLM slides on comfortably and tensions down solidly with no fuss. The surface under the anodize is remarkably smooth and devoid of tool marks, and any edges or corners that the user's forward hand have the potential to interact with are neatly executed. The two rail clamp bolts use a 7/64" hex key to tighten, and ended up just under flush with the opposite side, and actually allows small fore-aft placement adjustments for the entire SLM package before tightening the clamp screws; once tightened the solid engagement with the two screws and precise key cut clamp surfaces holds it in place securely. The 'wing's of the front sight to protect the post itself are concave from the inside face, with a sculpted flat outside edge - needless to say quite functional especially with the serrations continuing up the rearward angled face of them. Finally, the left side has elegantly subtle laser engraving with ROSCH Works SLM2 Made in USA markings. Arguably the best executed feature is the anti-glare serration of the angled rearward face, but it wasn't completely without issue for me.

http://i59.tinypic.com/2exv5s6.jpg

The only spot where I've had a partial issue is the lowest serration on the rearward face of the sight could be inadvertently displaced up, or even have that section stripped away while installing the light tube into the mount. Really minor concern, and I suspect a direct result of the serration 3-D location being determined for a different diameter of flashlight tube, not to mention total non-issue once mounted (since it's inaccessible and obscured by the tailcap anyway) but there is an outside chance of displacing that bottom strip of aluminum and getting a decent cut while installing and setting up the SLM2 system - I'm still really happy to see the thoughtful and time/cost inducing sight serrations on there, which puts the SLM2 in the argument for best fixed front sight even whilst ignoring the added capability of running a weaponlight through the body of the front sight.

http://i58.tinypic.com/23ral51.jpg

http://i57.tinypic.com/ajkv95.jpg

The included front sight post (although it's a bespoke sight post) is nearly standard width, which for myself alternating between the standard FSP type DanielDefense 1.5 Fixed Front Sights and the Knight's Armament Co. 45° Offset Folding BUIS with it's narrow SR-15 width FSP is actually quite usable. The post itself is a touch shorter than the standard offerings, primarily due to the flat bottom plane it sticks out of being higher because the sight base is also accommodating a flashlight tube (in this case 0.827" Surefire E series), as well as having a slight taper towards the top - the net result is actually quite effective. The base of the post is round and threaded into the base, but there is a roughly 0.0625" tall squared portion of the front sight post that can give purchase to a small square wrench, however a different tool (specifically a 5/64" kex key) is actually required to make adjustments. The front sight threads vertically into the SLM base, and is held in place with a nylon ball and set screw from the right side which holds the front sight in place by tensioning the nylon lock ball into place against the threads. This arrangement allows for extremely precise height adjustments, but did present a rather amusing problem for me personally.

The SLM2 I received had the set screw tension installed at what seemed to be the maximum torque spec for the set screw (or that somebody's idea of finger tight as recommended was a bit aggressive). The result was that the nylon ball intended to compress against the threading of the sight post wound up being compressed hard enough to lodge the ball itself in place preventing sight post rotation even after removal of the set screw - my resulting attempts to pry it loose with a paperclip wound up with me ejecting the small white nylon ball from the base onto some white carpet. Despite my 'brilliance' in removal, I did miraculously find the tiny (~3.5mm) ball and was able to reinstall it. With a bit less torque applied, the sight post was still held in place brilliantly, but I was able to much more readily make front sight adjustments by simply backing off the set screw a turn and being able to rotate the front sight post with fingers instead of resorting to multitool pliers. In practice, the best option for setting the front post height is setting it to flush then making adjustments in full turn increments until a more precise solid BZO is set with fine tuned fractional rotation adjustments, then running a dab of thread locker on the set screw once it's sorted (a tiny amount ideally, as one obviously doesn't want some excess Loctite 242 in the threading for the sight post itself). Though Rosch Works states the threadlocker isn't requisite for installation, I still consider this cheap assurance, especially considering the small size of the set screw and nylon ball it holds in place - same idea for the rail clamping bolts, as I don't want them going anywhere either.

The net result from all this is that with the Z68 Tailcap and KX1 head (as shared with the SureFire M300 Scout Light, for reference) the sight picture is remarkably uncluttered, with the front sight being quite prominent and quick to acquire as well as differentiate from the protective 'wings' on either side of the sight. The bezel of the weaponlight doesn't even protrude into the sight picture, which is already a net improvement over the X300/DD 1.5 weaponlight/front sight arrangement this is replacing because the latter ends up with both the bezel and battery door latch protruding slightly into the sight picture.

http://i57.tinypic.com/2m6shgh.jpg

http://i62.tinypic.com/wjgot1.jpg

With the particular sight radius of the weapon my SLM2 lives on (at the nose end of an 8" URX3 handguard) and rear sight aperture of the Gen1 MBUS rear sight, the top-most corners of the front sight 'wings' end up tangent to the hazy rear sight in a correct sight alignment, which is nice - but also very sight radius and ocular distance to rear sight plane for operator dependent. In short, the SLM2 has an excellent sight picture appearance when ran with fixed or folding BUIS, and with or without a holographic sight.

http://i58.tinypic.com/zjdjmh.jpg

http://i60.tinypic.com/sbmsgn.jpg

http://i57.tinypic.com/2qnprp1.jpg

Performance Testing

Performance testing a front sight with a relatively bulletproof flashlight still feels like the thinnest point of this review, simply because I haven't dumped a ton of rounds down the pipe of any weapon this is mounted to, and probably lack the budget to send enough rounds to even create a problem with such a stout setup. So far the most abusive test I've put the SLM2 through is getting up from a magazine supported prone position while using the shade of my truck's tailgate, and idiotically catching the front corners of the front sight wings on something. Aside from adding a slightly shiny spot where I broke through the finish and dinged the aluminum, the sight is none the worse for wear - the BZO hadn't shifted after that either - the truck now has a decent ding on the steel bumper too, so the worst part of that encounter was nudging my truck towards looking like the 21 year old beast of burden it is.

http://i57.tinypic.com/1z1xkt4.jpg

As far as actual shooting related performance notes, they're minimal. This is actually my favorite shape/arrangement for front sights I've encountered - not once have I mistakenly acquired a sight alignment and sight picture with my brain mistaking a protective front sight wing for the actual front sight. Lastly, the slight taper on the front sight is yet another positive feature, albeit a minor one. When used in conjunction with a micro Aimpoint attached via lower 1/3 cowitness mount the SLM2 sits happily in the bottom half of the optic's field of view, and using the Aimpoint Micro powered off as an oversized rear peep sight actually yielded adequate accuracy at 7yds. Ringing steel at 200yd to confirm BZO also went quite smoothly, considering that I was the weak point of that equation. In short, it performs as well as any fixed front sight could hope to, and considering my preference for weaponlight locations (and that every serious use carbine should have a weapon mounted white light) if running a fixed front iron sight setup is the best option, then the SLM2 is the best option among those.


More Images

http://i58.tinypic.com/169jhwo.jpg

http://i59.tinypic.com/ou63gy.jpg

http://i58.tinypic.com/2d9snxu.jpg


Closing Thoughts and Questions

- Who should consider buying the SL1, SLM1, or SLM2?
Anybody who wants or needs to run a 12:00 weaponlight mounting solution with a fixed front sight system, especially those with limited handguard real estate.

- Who the SLM2 is right for?
Any existing Scout Light users or shooters with a desire to mount an IR/White light 'V' series illuminator, or who wish to use the Scout series tailcap or SR07 remote pressure switches.
In short, any build where light weight, simplicity, and efficient use of handguard real estate is a priority, the cost for performance gained is really quite high - likely a reason why top carbine shooters like Mike Pannone seem to prefer running it.

The SL-1 complete system is still the best value and ideal answer for a pure white-light user seeking to set up an effective lightweight carbine, and the SLM1 equipped with a Surefire 6P-Fury or similar light is the best performance option for high output white lights, as well as being an excellent setup for activities like nighttime/low light hog hunting. The SLM2 really does fill a fairly small niche, but absolutely shines capability wise when compared to virtually any other weapon mounted electronics suite that provides infrared and visible spectrum illumination and laser designation when paired with things like the LDI DBAL-I2.


-- How does the LDI DBAL-I2 or LDI OTAL with RW SLM2//SF KM1 -LED setup compare with:
Here are my offhand notes on other complete Visible/IR Laser/Illuminator solutions that can be mounted on carbines and used in conjunction with iron sights.
My particular setup will be referred to as the SLM2(V) + DBAL-I2

- How does the SLM2(V) + DBAL-I2 compare to the Insight APTIAL-C + WML
The APTIAL-C has 3mW IR Illuminator output, KM1 pushes 110mW and can still use the larger bezel for a bigger reflector resulting in improved throw for hotspot. The latest civilian offering from Insight is really impressive, and the best civilian option for AN/PEQ15 choices; but the principal limitation I found when using an issued PEQ15 with my M16A4 was the lack of white light, and the AN/PEQ-16 was a particularly inelegant and ungainly solution to that problem (but that's what the grunt unit I was attached to had). For anybody running a setup like the issued Block-II Mk18/M4A1 with folding iron sights, or who prefers an offset mounted weaponlight, the APTIAL-C with those parts makes it preferable because of the varied switch/activation options; although the Unity Tactical Fusion mounting system makes a strong case for offset lights and integral front sights being ran alongside PEQ-15 type laser boxes. There are lots of great combinations, often similar to GWOT issued kits such as the Insight PEQ15, SureFire M300, and KAC Mk18/Mk12 BUIS, but few of those arrangements can be ambidextrously accessible on the 9.5" RIS-II handguard.
All that said, for symmetrical ambidextrous capability, switching simplicity, and complete cost: I'd put the SLM2 with KM1/KM2 equipped weaponlight and DBAL-I2 as the best option, especially since it's more immediately compatible with ultra-modern handguards like the KAC URX4, BCM KMR, DD SLiM, Noveske NSR, and others.

- How is the battery access?
On my 8" URX3 Mk18, with the laser box mounted nearly up against the LT660/T1, both batteries are easily accessible; not so with APTIAL-C.

- How does the SLM2(V) + DBAL-I2 compare to Wilcox RAPTAR Lite ES?
From my research, the REPTAR would still need KM1 head and DD or other Front Sight to match capability, but at a heavier weight. Adding the full rapid targeting rangefinding REPTAR to this equation makes it an apples to watermelons comparison, especially since expensive weapon mounted rangefinding systems are likely more at home on precision rifles with mid-long range variable magnification optics that are unlikely to rely on a fixed front sight base for backup sighting.


- How does the SLM2(V) + DBAL-I2 compare to the LDI DBAL-D2?
The DBAL-D2 is a behemoth and still lacks visible WML capability - this one is more apples and oranges, as he D2 fills a specific role very well, but they're not direct competitors.

- How does the SLM2(V) + DBAL-I2 compare to the LDI DBAL-PL?
The PL is intended as a complete IR/Vis solution for handguns and some PDW applications, and despite being very impressive hardware, the switches and access are quite tailored to pistol applications. For some it may be possible to run the DBAL-PL similarly to the X300 for mounting location(s), but the access to the push buttons alone seems to have prevented this from being an instant hit for carbine mounted applications. Coupled with slightly lowered outputs - again great figures for a pistol mounted emitter apparatus, but not ideal when talking about 300m effective engagement range - the most impressive part is that the whole package works, with a really solid white light emitter, but isn't really a direct competitor for an I2/SLM2 (V) either.


Until some firm sorts out an ideally tailored visible and infrared illumination and lasing system designed for carbine engagement distances with proper switching in a compact form factor, I believe that the SLM-2 provides the best option on the civilian market when paired with a dual output Surefire Executive tactical light and Steiner eOptics (formerly Laser Devices Inc.) Class-1 dual-beam unit.

Disclosures:
I wanted to guinea pig the Surefire Executive compatible version of the Rosch Works SLM so badly that I badgered Don into sending me one of the first models ready to be released into the wild. I did purchase the SLM2 and set of 1-cell and 2-cell light bodies at below suggested MSRP directly from Rosch Works in order to complete this review.
The SLM2 is still mounted on my personal Mk18 silhouette carbine.

Uffdaphil
24 February 2015, 15:17
Thanks for that amazingly comprehensive review. I bought the SL1 when they first came out and am happy with it. But the ability to choose my own light and replace as desired adds the SLM1 to my wish list.

GOST
25 February 2015, 04:39
Very nice review TehLlama.

UWone77
26 February 2015, 01:02
Wow... great review.

rob_s
26 February 2015, 04:24
I've had a couple of thee, both the integrated light model and the one like this to hold a Surefire.

While I find the concept to initially be sound, I found it to be lacking both in conceptual form and in application once I started using it.

Conceptually, I have since tpdetermined that I don't want my light and my sight to be a single unit. Reasons are multiple, but primarily I don't want to have to lose my sight/zero if the light needs off-gun maintenance, and I want my light to be easily removable to use on other guns or even handheld if requeired.

In application, I found the execution to be lacking in that it was simply unbearable to zero. I'm sure I was doing it wrong, and some have made the argument that you only zero once. Maybe, but I found the process so painful that I didn't even get a hard zero the one time, so I find that argument flawed.

For me, the A answer is still a locking, foldable front sight and an X300.

CK 187
26 February 2015, 07:53
That is a top notch review!!

TehLlama
27 February 2015, 09:37
Rob,
The remainder of my carbines are all offset sight or DD Fixed + X300 equipped setups, but for an 8" URX3 setup those compromises are a ton better than the loss of effective real estate. It's kinda a one-and-done zero, and from there the light body becomes basically a captive part of the front sight, but that's a tradeoff I'm totally willing to make since I have WML's on every secondary weapon (X300), and tertiary lights (E1s) as integral in every make/stop/plug holes capable kit. The X300's are all removable on the secondary setups, and if I need NVG compatibility with those I can move to X300V's pretty easily too.
My de-facto standard is either a folding front sight in front of an M300, or folding offset sights (KAC) basically mounted under the tailcap of an M300. I know where you're coming from, but for compact or really light stuff where making the WML captive and having a slightly more complicated front sight: completely worth the tradeoff/

Jerry R
27 February 2015, 13:03
This review is very nicely done! Thanks.