Gear Review: Crimson Trace Rail Master Pro


Shortly after my wife and I moved into our new home, I was in the shower around 10:00 PM on a weeknight when my wife came in to tell me that somebody was banging on our front door. I rinsed the shampoo out of my hair, dried off, put on pants, grabbed my FNS 9 and Streamlight TLR-1 from the bedside table and headed downstairs to see what the commotion was about. Fortunately, the doorknocker had left, but I realized that I needed a better lighting situation as the TLR-1 that I have is the GameSpotter edition which is a bit large, and hard to mount to a pistol. I mentioned it to Nick and the next time we saw each other he tossed me a Rail Master Pro to try out…


With nearly every modern handgun sporting a section of rail under the barrel, it only makes sense to offer a universal fit light/laser combo that can fit a variety of platforms including pistols, rifles, and shotguns. For the purposes of my test, I mounted the RMP to my FNS-9 as well as my home defense AR. The RMP ships with a variety of different keys that fit in the top to allow near universal fit.


Mounting is fairly easily once you pick the right key, the manual gives a thorough overview of how to pick it, so very little thought is required. Mount it up, and use a thin straight bladed screwdriver to tighten it to the frame. The RMP is activated by either of two paddles that are situated near the trigger guard if mounted in the above configuration. Tap quickly for on, and then hold for a moment to turn off. The RMP has four modes, 1.) light only 2.) laser only 3.) light + laser and 4.) strobing light + laser. Adjusting the laser is very easy using the supplied tiny hex key. I found the easiest way was to rough it in using the existing sights, and then shoot it to finely tune it. I managed to sight my FNS-9 in using less than 10 rounds. If you have a sandbag rest, it can go ever faster.


The 100 lumen light is just about perfect. Bright enough to make target identification a snap, but no so bright as to sear the retinas. The strobing function is very disorienting from the operators perspective, and I image int to be seizure inducing from the muzzle side. In the dark, the laser casts a beam at least 100 yards, and in the bright daylight, the red laser that I tested could be seen at 10 yards. I think that’s more than enough in both situations. I was unable to the shake the RMP loose or otherwise break it during my testing. I did manage to kill a battery, but I’m pretty sure Leghorn handed over a nearly dead battery to start with. It did expose a nice piece of engineering in the built in low battery alert, the light and laser flash when activated. Once I replaced the battery, the flashing went away and I’ve been unable to kill a battery since.

Specifications: Crimson Trace CMR-204 Rail Master Pro

  • Material: Polymer
  • Attachment: Rail Attachment
  • Battery Type: One CR2 Lithium Battery
  • Laser Output: 5mW Red Laser
  • Activation Mode: Switch Activated
  • Warranty: Three Year Full Warranty
  • Color: Black
  • Dot Size: Approx. 0.50″ at 50′
  • Light Output: 100 Lumen LED White Light
  • Price: $279.00 from Crimson Trace $225 from Amazon $199 from OpticsPlanet

Fit, Finish, Quality * * * * *

Simplicity is best, and the RMP delivers. Simple on/off activation, and easy installation means an easy to use piece of kit. I found it to be easy to sight in, though I’d prefer that Crimson Trace marked the body of the RMP with indicators to tell you which screw is windage and elevation. Once set, the RMP never lost zero.

Form * * * *

The problem with making a universal accessory is that it is universally not going to fit as well as something designed for that particular platform. I think that Crimson Trace has done an admirable job of building a laser/light combo that fits a lot of rifles, shotguns, and pistols without being too cumbersome. I did find that it was a bit of a bulky accessory for my AR 15 though. It just sort of hangs out awkwardly on your rifle of choice, but works well.

Accuracy * * * * *

The RMP doesn’t have a problem holding zero once set, but the one issue I had was setting it up on the FNS-9 which has always had POI below POA using a sights under bullseye hold. What this means using the RMP is that you can’t see the laser while using the irons. You need to pick up your head to see the laser which isn’t ideal. Other pistols might not have this problem.

Overall Rating * * * * *

I think this is an outstanding accessory for the shooter looking for a compact light/laser combo that they can attach to a variety of platforms. At $279 or less, it is a versatile purchase that can be used across multiple guns. I was unable to break it, or make it fail in any way whatsoever, and it has now become a permanent fixture on my home defense gun.


  1. Eric

    How does one switch between modes? Do you pick a mode and then that mode is the on/off selection from that point on?

    1. Tyler Kee

      Yep! Once you have it “on”, you hold both paddles and it’ll switch to the next mode in line. That’s the new mode when you switch it on or off.

      1. Eric

        I prefer all weapon lights to be press on, let go off. It just makes the most sense to me and I am not switching from my TLR1 with Grip switch on the Glock.

        1. SnJohnson

          For the price I would just get a Streamlight TLR-4. It does everything here except strobe, and it’s 200+ lumens and only $120. And by get a TLR-4 I mean I would purchase more in addition to the ones I already own.

  2. Sian

    This is 2014 why does anyone still use flathead screws? square/hex is not only superior but also looks way nicer.

    1. archangel187

      My Victorinox knife doesn’t have either of those, but it does have a flathead piece.

    2. Scrubula

      Flathead can be removed and tightened with random objects. Coins, any flat piece of metal, etc. It also resists stripping out more.

    3. RandallOfLegend

      Flat head screws are more compact. Flat and button head hex screws are prone to stripping.

  3. Roll

    AR, Tyler, you need to grab your AR w/ a weapon light next time.

    1. Tyler Kee

      At the time of said door knocking, the AR was bundled in storage. Not so much now. The aforementioned TLR-1 is back in action there with the momentary on/off switch.

  4. ST

    The laser also makes a great dry fire training aid.

  5. Missouri Josh

    Some of these laser/light combos can reach almost $400 at my LGS. I just can’t see dropping $400 for one of them little stinkers.

    But at $279, or even $199, I’m game.

    Strobe function, though? Hmmm… would that feature be filed under the “just nice to have” or “just because” section?

    Supposin’ it has a usage while listening to ridiculously loud house music.

    1. Anon in CT

      Green veson of this one is close to $400.

      But it’s Green!

    2. Gunr

      A $400 laser light on your $150 Hi Point, might bring out the “Bad” in you.

  6. Sixpack70

    This story reinforces my thoughts on a “toilet gun”. I had a conversation on G+ with a few people on a gun in the bathroom incase you are showering or sitting on the pot. I was thinking of a small 5 or 6 shot revolver. I’ve seen EAA Windicators for a around $270. It’s in .357 magnum and not very large. Taurus and Charter arms also make a small .38 revolver perfect for the bathroom. Put it in a plastic freezer bag and hide it under the sink somewhere. It shouldn’t rust and it’s right there for when you are in the shower with soap in your eyes and a meth heads beating on the door.

    1. ChiGurh

      You are a smart man. I, too, have thought about various situation in the house, and which one you are more likely to be caught with your pants down, and the bathroom takes the cake. Small room with confined space, only one way in/out, a place where you spent a decent amount of time. Overall, it’s probably the worst spot to be in if a sudden, unexpected invasion occurred. I have various areas all-around the house where I keep weapon as to be sure that no matter where I am in my crib, if something were to go wrong, I will be in a 10 ft. range of something to defend myself with.

      1. archangel187

        Good thoughts. Though I must say if you have an expected home invasion there’s a lot of other things you’re doing wrong. Reminds me of Rocco from the Boondock Saints: “Pack yer sh*t! Pack yer sh*t!”

      2. Gunr

        Where to hide your gun?? If it’s small like my NAA mini revolver, hide it where the ISIS terrorist hide their money,………………………………..under the soap!

    2. Gunr

      You might not have time if you have to fumble around with one of those freezer bags, Better to have stainless steel weapon and hide it under a wash rag.

  7. Dave

    I waited months for this to be released by CT and thought the combination of light and laser was a great idea.

    Was very disappointed and returned it within a few days when I found out it did not have a “momentary on” switch.

    In all of the low light shooting classes I’ve taken (4) the instructors have stressed, and I have seen the value while shooting under stress, of momentary contact. On/off switches=no bueno. For me at least and per what the instructors said and owned themselves.

    I contacted CT and they said there were no plans to add a momentary on mode, so I’ll just stick with the Lightguard mounted on my XDM 3.8 and live without the laser.

    1. jack in the Crack

      A momentary-on feature would necessarily involve an additional switch located on the grip. (Otherwise the user would be faced with the impossible task of holding a button on the device while aiming and shooting). I have a number of crimson trace devices on CCW pistols and revolvers. Each has a small “button” that is depressed (by the middle finger) as an incident of gripping the weapon in preparation to shoot it.

      In each instance the device is specific to the model of weapon and the momentary switch is integral to the molded part(s) that are attached to the weapon. It would seem all but impossible to create a momentary-on switch that would universally fit the types and kinds weapons that Rail Master Pro is intended to be fitted to. Specifically in that a wire of some type would be required to be mounted from the Rail Master Pro to the momentary switch on the grip.

      The prospect of a random electrical wire being strung along the trigger guard in order to place the momentary switch surely makes the product liability exposure alone a deal killer.

      You will probably have to buy a device specific to the weapon to get that feature.

      1. Dave


        I disagree with the momentary on capability requiring a proprietary switch. I own the Surefire X300 Ultra, which is a universal fit, although a light only. For constant on, you press the side switch down (or up). For momentary on, you press in (on either side). The cool thing about this is you get momentary on and can maintain almost all of your normal grip on the weapon.

        So you can get momentary on in a universal fit light.

        1. jack in the Crack

          It looks like the momentary switch protrudes a bit into the trigger guard. Makes sense and does not look like a problem liability wise.

          I’ve never seen one like that before, thanks for responding.

  8. Mike Gruber

    I have a CT railmaster and have burnt through 3 batteries due to the momentary on paddles with no lock out like their light guard. I also have not been able to find a holster that doesn’t also inadvertently turn the light on. I bought the railmaster b/c of its smaller length for my g30s. I will be looking at the trl-4 next. Any comment on the inadvertent light issue on the pro version?

    1. Dan A

      Yeah, the paddles on the original RM activate if you so much as give ’em a dirty look. On the RM Pro they take a bit more force

  9. DaveM

    Wife reports some one banging on the door and you rinsed, dried and dressed then obtained firearm and light
    So you skipped the conditioner part while some one was banging on your door?
    How big is your new house?

    1. Gunr

      Yeah, I think if someone was “banging” as said (not knocking) on my door, at 10 pm, I wouldn’t worry about drying off and all that stuff. Grab a towel and get to where ever your gun is, PRONTO!

  10. md matt

    Got my insight m6 which has both momentary and constant on functionality.
    Better than this imho.

  11. Yngvar

    This was interesting. Is there any possibility to tune the light (intensity/spread angle)?
    As an aside – I would expect my missus to act more pro-actively than ‘a barking dog’?

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