Gas Tube Bender
I made one of these for myself a couple years ago and it has worked so well, and I've had so many people ask for one, that I ordered some steel and made a small batch. It is a gas tube bender, and it looks like this:
It's for those times when bending the gas tube is the only way or the only way there's time or tools for. Sometimes there's just no getting perfect alignment, or maybe the gas tube has been bent out of shape. A certain amount of 'touch' will pretty much always exist between the gas tube and the carrier key spigot. There's just no way everything could line up perfectly. The carrier is not a super-tight fit in the upper receiver, and the gas tube is not hard-located in the upper receiver. The gas tube being a long skinny piece actually gives us the little bit of flex we may need as the carrier key spigot telescopes over the gas tube... unless things are out of alignment to the point where the gas tube runs out of flex and wiggle room where it passes through the front of the upper receiver. This will cause bind as the two parts meet--in extreme cases it will be enough drag to impede function; in other cases it will cause wear on one side of the gas tube, resulting it a reduction of gas channeled to where it needs to be to function the action, and increased fouling of the interior. In this situation you either fix it upstream, as in, maybe you just had the barrel off or changed barrels and the barrel nut notch on top is not top dead center and is jinking the gas tube. Maybe you've got a gas block that is not positively located with pins (set screwed or clamped on), and it is off to one side, jinking the GT end to the other side. If fixing these doesn't do it you may need to bend the GT. You can do it with screwdrivers, but it's a little imprecise and if you need up or down, moreso. I find it tricky and difficult. Plus it looks really, really bad if your customer is looking over your shoulder. To bend the GT up or down using the GTB, slip the two-holed end over the GT and push forward to bend down, backward to bend up:
To bend it to one side or the other, use it with the two-holed end up. The large hole is for the bolt tail or other leverage cheater--put it in and start bending.
The test is, with the bolt removed, run the carrier in and out. Feel, look and listen for when the carrier key spigot starts to telescope over the GT end. Bias the carrier left, right, up, and down in turn. Like I say there will always or almost always be some contact and maybe even movement of the gas tube, but try to get it minimized, and equalized on all sides. After that, GT flex and movement should allow decent alignment.
For now I'm pricing these at $30 which includes shipping.