Problems mounting weapon light on barrel?

[jstephens202]

What are the problems, if any, with mounting a weapon light directly to the barrel? I have read some say no others say yes. I currently run a Surefire mounted on the barrel of my carbine just ahead of the bayonet lug and have had no problems accuracy wise, at least that I can tell.

[Belmont31R]

I wouldnt do it on a precision rig but on a fighting gun its probably not going to have much in the way of a noticeable effect. Anything touching the barrel will alter its harmonics during firing. Sometimes that can help, and other times it can make the barrel shoot worse. If you don't have a problem doing it then don't worry about. Dealing with this type of thing its important to have consistency. If the barrel harmonics are the same shot to shot then its predictable. If you have torque on the barrel one shot, and none the next you are going to alter the POI. That can happen through things like bipods, slings, shooting position, etc.


One reason why precision bolt guns generally have a large barrel channel in the stock so any pressure on the stock doesn't transfer to the barrel, and why synthetic stocks are so popular. Wood has a tendency to warp based on environmental conditions, and would affect POI. Like say you zero the gun when its dry, and then go hunting in the rain. The wood swells, and changes the barrel harmonics.

[spamsammich]

If that is a gun you will be training with and subjecting to sustained fire, I would be more worried about the heat transferred to the light than the accuracy.

[RB-S13]

If that is a gun you will be training with and subjecting to sustained fire, I would be more worried about the heat transferred to the light than the accuracy.

+1

That bitch is gonna get hot.

If its just a house gun or a fun gun I guess it wouldn't matter.

[Failure2Stop]

You will be much more likeley to alter POI if shooting through small ports, and you will be transferring a lot of heat to the light body.

[Bimmer]

What are the problems, if any, with mounting a weapon light directly to the barrel?

None, that I can tell, for my situation...

I have a TLR mounted at 12 o'clock in front of the FSB on a rail section bolted to the barrel. I have orangutan arms, and I can easily reach the switch on the back of the light with my left hand.

I'm not worried about pin-point accuracy if SHTF — I can't see more than 50-75yds with the light, and the longest line of sight in my neighborhood is barely 100yds.

I'm not worried about it getting hot, either, because I take it off when I shoot during the day. If the SHTF and I'm firing so much (and so fast) that the barrel gets hot enough to cook the light, then I'm probably done trying to identify targets, anyway.

This is my thinking, anyway...

Bimmer