The Ultimate Firearms Destination for the Gun Lifestyle

A look at SureFire’s new X400 Ultra with Green Laser

SureFire has expanded their X-series of WMLs (Weapon Mounted Lights) with the new X400U GN. The X400U GN is largely identical to the X400U RD it follows, just with a green laser instead of red. Light on the green spectrum is far more visible than red to the human eye (one reason trackers use green light at night on follow-ups) making the green laser easier to “pick up” under stress than red. This also makes it easier to “chase” than red, but that is a different topic entirely (and in some ways a training issue besides).

The X400U-GN attaches to both Universal and Pic rails. It has a 5 milliwatt/505 nanometer green laser (5 mW / 505 nm) generated by a green-laser diode rather than double YAG, which is big brain speak for “it should be more reliable over a broader temperature range” than many of its competitors. (I’d have to bring in some one more up to speed on this stuff to drop the science of solid state lasers on you, but it boils down to the lasing medium used when it is generated.)


SurefireX400U-GN-2 Like its predecessor, the new X400 utilizes Nylok screws in its adjustment mechanism. SureFire advises the Nylok screws won’t back out from the effects of recoil so the laser will retain zero longer. Similarly the light itself uses a 500 lumen “recoil proof” LED that delivers white light through a TIR lens; they describe the beam as “versatile”, with “significant reach and surround light”. I’m extremely happy with the illumination power and delivery of the light as well as the ease with which the laser can be tuned, but I need to put a lot more rounds downrange before I can attest to whether light and laser are in fact recoil proof or hold their zero (nor have I burned the light long enough to see how long it will run, though can be very dependent on battery quality).

That said, my X400U-GN has experienced about 150 rounds thus far (evenly divided between 9mm, .40 and .45) and I’ve had no malfunctions (or NDs) with the light. I will try to increase that by at least a factor of 10 before reporting back on how it performs. So far so good though.

More details via SF: Power is supplied by two disposable 123A lithium batteries, which produce tactical-level output (enough to overwhelm an aggressor’s vision) for up to 1.5 hours. Activating any X-Series WeaponLight is achieved via an ambidextrous push/toggle switch located on the end cap. For additional control, without the need to alter your grip on the weapon, X-Series lights can be outfitted with optional SureFire DG grip switches on many popular pistol models or with SureFire XT pressure-pad tape switch on long guns…[It is] constructed of aerospace aluminum, hard anodized with a Mil-Spec finish, and O-ring and gasket sealed to keep out the elements…

Assuming the X400U GN maintains the level of quality and durability I’ve previously experienced in SureFire products, my gut tells me it will be a winner. Use of the laser as a training tool on the square range aside, I think once again this is going to boil down to 1) understanding how a laser does and does not work in a fight and 2) whether the individual user prefers lasers and is willing to train with them. After 2+ decades of not using a laser except under special conditions (classes, T&E, etc.) I personally have a hard time not chasing it; I’m also slower engaging a target with a laser than without – which for me  (and this may be far different for you) is not actually a huge issue. I would not be using it except in specific circumstances. For instance, once upon a time many years ago I used a red laser a handful of times when responding to fights/domestics with weapons within a trailer park – I did this because I was worried about throwing an airball and hitting Aunt Pootie or her grandchild 3 trailers over and because a Hollywood-trained public often respond to a visible laser by deescalating.

BBC & Graham Combat

I use the white light, conversely, all the time – the laser is a handy add-on that increases my tool’s versatility. I think it also worth pointing out that I’m carrying an X400U in a Raven Concealment passive retention Kydex holster. I would not be able to (or at least would not recommend) carrying a weapon/X400U combo on duty until there are Level I or II retention holsters available for it (and there may well be, I just haven’t found one yet).

More to follow in the coming months. In the meantime you can learn more (or order one) here:


Pictures courtesy Mia Kiddo.

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