I've removed one FSB so far, and that was on a barrel that had already had the FSB removed once before by a previous owner.

I've recently decided to transform my existing Block 1.5 into a Block 2, since I got a newer 6920 lower to make into my Block 1.5 like I carried in Afghanistan.

Removal of all my exisitj g parts was going good until I went to remove the FSB since I'm using the DD RIS II FSB. Sweet mother, I can't get the pins to barely budge. I even went out and bought a different punch set to try. Got them to budge a little bit, but am I supposed to be hammering the ever loving crap out of these?

I've currently got some automatic transmission fluid soaking on it, any other suggestions short of sending it off?

Ensure that you have the barrel and FSB secured, any movement will reduce the force applied to the pins, and use a heavy hammer (more than what you think you may need).

What I've started doing to get the pins moving is throwing it in the vice. I angle it just enough that I get one side on the large end of the pins and the other side is gripping just below the pins on the other side.

Crank down (if you have a decent vise you should be okay) and watch the magic happen. Not the professional way, but it's worked on quite a few FSB for me.

I have a very large brass punch that I use, along with a small 2lb sledge.  The brass punch serves two purposes.  It gives a slight deadening effect, which helps keep the punch from bouncing off the taper pin, thus transferring more energy to the pin.  It is also is less likely to slip off since it conforms to the pin head somewhat.  Since I started doing it this way I have yet to find a pin that didn't move on the first whack, Colt and BCM included.

I have a taper pin punch and a ball peen hammer.

Quite a coincidence as I got a Colt SOCOM barrel off the EE that arrived today and I made a video on how to remove the FSB pins. I'm editing it and I'll share it on here once it's done.

Edit: here is the video

https://www.youtube.com/watch?v=ZagROtSCxlw&ab_channel=TacticalLobster

I'm sure you know but make sure your hitting it on the small end of the pin

I have done a few and never had a problem.  The other day, I decided to take a railed upper and install a front cap so I could put some standard hand guards on the rifle.  It was the most difficult one to get started, and after torquing the barrel nut, I was anxious to get the FSB back on, and forgot to install the cap.  As I was attempting to remove the pins again, I was having an even harder time than at first, and the pins were not even as deeply seated as they originally were.

Long story short, I was mushrooming the punches I was using.  I took them out to the grinder and put a sharp face back on them, and they worked like magic.

Would soaking it in that Kroil stuff or whatever it's called, help?

I've only removed one but I had to hammer the shit out of it.

That would push the pins in farther.