So here I am, attempting a first time front sight removal to slide on a free-float hand guard. (16" light weight SGW stainless barrel)
The g!!!@#$%^d f!@#$%^&g gas tube refuses to budge from the front sight.
Yes, I popped out the retaining pin and yes, I've got one of those gas tube gripping thingies from Brownells.
Any suggestions, special tools, or cyanide tablets out there?
Also, any suggestions for getting the f!!!@#$%^&g front sight retaining pins out would be much appreciated.
Thanks in advance.

Do you have a vice? Turn the upper upsidedown and clamp the gas tube in the vice. You need to clamp the portion of the tube with the jag in it. The tube will be horizontal, within the entire width of the jaws. Tighten enough to support the upper. If you need to reuse the tube, and the jaws are serrated, you can protect it with aluminum jaw covers (1" or 1-1/2" angle works good). Twist the upper back and forth to twist the tube loose in the sight.

To remove pins, The sight needs to be resting on something dead solid. A slight springiness in the supporting surface can ruin your efforts. Many vices have a small anvil surface in the back. Make sure there is clearance for the pin to exit. A short starter punch is less likely to bend. The pins are tapered. strike the small end.

Thanks a bazillion. Your methods worked great for removing the gas tube and front sight.
Next problem: Apparently, the genius who installed the barrel never heard of anti-sieze thread coatings. I've worked for about 45 min and have so far succeeded in rotating the barrel nut about 45 degrees. I'm starting to worry about tearing the wrench lugs off the barrel nut.
Any suggestions?
Thanks again.

Glad I could help, SailorDude

That doesn't sound good (the barrel nut problem).
I assume you are turning it correctly (counterclockwise as viewed from muzzle end).
Are you holding it by the barrel or by the receiver?
If you are holding the receiver it should be loosening after that much rotation. If you are holding the barrel, is the receiver turning along with the nut? It should not be, as that would indicate that the index pin in the barrel has been sheared off. In that case you will need to use a receiver block to hold it.

RJL357: I'm using one of those fiber blocks that holds the reciever in a vise. Like I said, I've gotten the nut to rotate about 45 degrees and it just won't go any further. I've also broken two of the teeth off the nut in the process.
Any miracle chemicals out there?
Thanks again.
SD

try a squirt of pb-blaster. i used a breaker bar on my stubborn barrelnut. there should be a 1/2 inch square cutout on the barrel wrench for a breaker bar and torque wrench. have a friend push the barrel wrench end flat against the barrel nut, while you break it lose with the breaker bar. when reinstalling the barrelnut,i use permatex copper anti-seize lubricant from an auto parts store.