I wanted to swap uppers install the Holosight and it’d be my wife’s weapon.
I looked at the Brownells youtube video and the guy removed the FSB/gas tube to get at the barrel nut and delta ring in a float tube swap. Thought that looked like the way to go, as I wouldn’t have to purchase/wait for shipping as he replaced the FSB/gas tube as one unit.
Of course on the video, one whack and the taper pins dropped…
i guess it depends on how well
your shop is set up.
i searched for "front sight base removal "
and got a few threads that have all the details
you probably have on your mind.
it’s worth a look.
No need to remove the FSB unless you’re installing a one-piece freefloat tube.
If you’re just swapping uppers, the easiest procedure is to leave the FSB in place and just remove the gas tube.
Something to try before either just giving up or cutting it.
Use two short pieces of wood cut from a soft pine 2X4, a vise and a non-marring heavy mallet - or just a length of 2X4 you might have left over.
Place the two pieces of wood in the vise, flip the upper upside down and tightly pinch that portion of gas tube nearest the FSB between them. You should have a full 4 in. of gas tube sandwiched between these two blocks. Due to the softness of the wood you’re minimizing the risk of damage to the tube, so go ahead and make sure you get it very snug.
Now smack the rear of the upper receiver with your mallet or board. A good solid blow or two should break it loose.
Good idea, tried it to no avail…'99 BM, guess it’ll remain as is, and I’ll put together another upper… I guess “if it aint broke, don’t fix it…”
Thanks for all your time and effort folks !
People are going to cringe when they read this but. The best way to remove a stubborn gas tube is to take a pair of vice grips and clamp the tube and use a small hammer and tap on the vice grip. Gas tubes are not as delicate as most people think.
5pins,
I was hesitant to post that because I didn’t to be accused of heresy 
but I do it like this as well if I have a hard one. If the tube is too difficult I cut it and rip it out.
I did that but using a channel lock instead, due to the Breakfree that I’d sprayed on the FSB/gas tube, the channel lock just slipped and scratched the tube. That’s when I called it quits. When my current build is complete, I’ll get after those stubborn parts on the BM.
Wipe the tube off, put the vise grips about 1 inch behind the FSB and lock it down. Then wiggle the vise grips back and forth and it should loosen. Don’t worry about scratching the tube. Just don’t damage it.
Also, I’ve found PB Blaster to be much more effective at loosening gas tubes than Breakfree. Plus it kills spiders and all sorts of things.
And you can always use it on your cars! It’s a good product that does as advertised.
I feel your pain sir. I helped a friend of mine remove the FSB on his gun last week. The first pin came out after a lot of taps with the rubber mallet and pin punch. The second one wouldn’t budge. I cussed and smacked the pin a bunch more times, even with WD40 soaking the pin area the pin wouldn’t move. We soaked the sight in oil and went to get some ribs. An hour later with my belly full of bbq ribs, I decided to give it a few more taps. The stubborn pin finally came out. So the trick is bbq ribs and WD40! Hope you already got them out by this time.
Kroil + Taper Pin Starter + Front Sight Base Bench Block + 3 lb sledge = success every time for me.
I had a buddy bring over a BCM middy upper he wanted to put a rail on. I flattened one of those Starrett taper pin starter punches. It’s no longer cupped… lol. We ended up using a press to get them out. I wish someone would fab a good fixture just for using in a press for this task.
Did you try using penetrating oil first?
Pretty much abandoned the idea…
Gave the old BM a camo facelift and installed the Holosight on the rail in front of the carry handle, it worked fine, bagged a hog with it last week.
Thanks for all the ideas, much appreciated!
I couldn’t find any Kroil but I did spray some WD40 on it and let it sit. They still wouldn’t come out without the press.
In my experience, WD-40 is useless as a penetrating oil. Kroil or PB Blaster are much more effective. I removed some rusted taper pins that had been painted over after nearly killing a Spring Tools nail set. Soaked the pins in PB Blaster overnight and in the morning the paint had been eaten away and two taps from the nail set and the pins popped loose.
I’m sorry to hear that you are giving up the idea, wish you wouldn’t, give it another try.
After reading the horrors posted here, I don’t feel too bad now that it took a lot of sweat, swearing and hammering to get the pins out of my buddy’s sight tower.