Which mount do you prefer for a Glock and why?
Per the Big Tex Outdoors blog post:
The X300U-A uses the older style Rail-Lock® Mounting System. which is best suited for polymer framed handguns.
The X300U-B uses the T-Slot Mounting Rail System which is best suited for metal framed handguns as well as AR-15 or similar style rails. The T-Slot system is also used on the X400 series of weapon lights. The main issue that people had been experiencing with the T-Slot style mount on polymer guns is the overtightening of the light causing reliability issues with the gun or under tightening of the light causing the light to come off. The Rail-Lock system is definitely prefered for use on polymer framed handguns but for use on an AR, the T-Slot has some distinct advantages.
I have asked a few trainers which to choose for a Gen 4 G19 and all said the A.
I agree, for a Glock I would go with the A model. For any metal frame guns the B model is superior for sure.
Sent from my iPhone using Tapatalk
The A model will fit many more holster options with glocks. I use a models for glocks and b models for ARs and other pic rail pistols.
Sent from my SM-G950U using Tapatalk
Ok. I’ll be different. Being a streamlight user, I stick with the t bolt mount on the X300 as well. And I shoot Glock.
I’ve been using a X-300U-B on my G17 for awhile now with zero issues.
I use the B model on polymer and metal frame guns with no problem. The A model can have a loose fit while installed that doesn’t go away. The only advantage to the A model IMO is being able to quickly remove it without any tools if you need a handheld light.
-A model just because I’m still using the 200 lumen X300.
A model.
It damages poly framed railed handguns less.
It can accepted the Unity Tactical hood so I can use it on a rifle. IMHO, I don’t even see a need for the B model to exist.
I just did some rough digital caliper measurements on my Gen3 G17 and found the following:
A vs decently (correctly!) tight B
- Frame above the rail = ~0.008"
- Frame around the front slide rails = ~0.005"
These are a rough in my mind mean of multiple measurements not using any repeatable scientific method. The frame did compress, but not very much… My guess is that a randomly tight A would have the same effect. I wonder what the tolerance of Glock slide rail location is??
More importantly I have had a B model on my duty G17.3 for at least a thousand rounds with no issues. Although I can see how you could have issues if you seriously overtighten the screw and maybe cause rubbing or frame failure over time?
Dennis.
Sent from my SM-G955U using Tapatalk
Because the A doesn’t work well on lots of metal frame guns. It is also easy to strip out the tiny screws on the A when changing keys between the U and P.
Re-thinking this question, I would not buy an A anymore. The B is much more versatile and will fit everything on the market.
Sent from my iPhone using Tapatalk
I hate the A Model.
The B-model fits tight on everything and is easy to install.
The only A model I have is a old 170lm unit on a Scorpion, because it’ll likely never get used for anything at night but just in case.
When I bought my Ultra, I wasn’t even aware that there was a B model. At first, I as skeptical of the design but after three years and many, many rounds it is still solid. I do like the relatively easy and tool-less removal of the A model, though- mine now hangs off of a HK45 for which I have light and non-light holsters.