Okay... I've only done 3 of these before, but none have been this hard to get off. I'm sitting the barrel on a piece of wood on a concrete floor and the bayonet lug on a piece of the same wood (1/2" thick?) to make it sit straight while I use a good sized hammer and one of the brownells cupped end punches specifically made for this purpose to whack the heck out of the pins. Well, that's not entirely the whole story. I've tried using penetrating oil (wd40) on the pins for one hour, two hours and 24 hours to loosen them up. No luck. I've tried using the specialized plastic brownells fsb support thing so I could get a _really_ good whack on those pins. No luck. I've also tried using an oversized brass punch (not cupped end). The punch now has a cupped end. :-)  At least I haven't mushroomed the pins. I had a feeling the brass would give 1st and was right. Soooo... after trying the penetrating oil the other day, tonight I got out the propane torch and tried heating the area to see if that would make it give up and come loose. No luck. At this point I'm all out of ideas short of trying to find a way to use a sight pusher or something to rig on there... or the last resort that I really don't want to have to do... drill them out. Anyone got any other ideas? As I mentioned, I haven't mushroomed the pins or anything and I'm definitely driving them in the right direction. I measured the ends to be sure. BTW... this is a Colt barrel. I'd always heard that the Bushmasters were the hardest to do, but maybe that's not always true, huh? hinking.gif
Help!?

Try freezing in your freezer. I have a feeling the shrinkage might be more useful than the heat expansion.

I wouldn't suggest you go as far as using liquid nitrogen, like I did... it did work, though.

Let me guess - A Bushmaster barrel right?  Same problem here, I couldn't get the front pin off no matter what.  Other members had suggested the ultimate solution is to cut the FSB off and install a new one with either set screws or use the "clamp on" type similar to Armalite FSB.

Use Kroil instead of WD40 for penetrating oil.. available from Brownells.. works great on roll pins also.

WD40 is very limited (IMO worthless) as a penetrant fluid.

Good Luck.

Bravo5-2

Filter through this thread.  I remove FSBs all the time and have yet to run into a serious problem.  Not saying the toughy is yet to come my way, but it hasn't yet.

FSB Removal