I want to do this, but I've never done this before.  How difficult is this?  I'm not a gunsmith by any stretch of the imagination....

Cake...

pop the pin for the gas tube

pop the two pins for the front sight

remove the flash hider, remove the front sight..

put on your gas block if you have screws make em tight...

if you have pins, mark and drill for new pin holes and put in the pins...

gas tube back, pin back, flash hider back, test....

Let's say you're gonna replace a FSB with a low pro gas block to fit a longer FF tube ala the rifle length on a carbine gas system.

If you remove the handguard cap then install the new gas block  all the way to the barrel shoulder, will you risk closing off the gas port?  If so, how much distance should you leave between the shoulder and the gas block?  That is, how "thick" is the average handguard cap and does it make a big difference?

I ask because I'm looking at a mid-length barrel, DD 12.0 tube and a PRI steel gas block on my work bench and am preparing to build this rifle.

Quoted: I want to do this, but I've never done this before.  How difficult is this?  I'm not a gunsmith by any stretch of the imagination....

What are your plans for your old FSB? You looking to sell it?

Gene

No seriously, I have a standard fsp and i'm thinking of changing to a gas block of some kind.... but everywhere i look there arn't any instructions like they have at the top of the Build it yourself, they have shaping your own post but not installing a new one..... someone. help!

Well I took my first one off a few weeks ago ( I tried for about 4 hours one day the first time and only got one pin out). I'll give the steps I did and what worked for me, now keep in mind this was my first time and this is my first AR, but I did some reading on here and took the pointers I could find.

-remove the the barrel from the upper receiver (not mandatory, but it made it easier for me this way) If you don't know how to remove the barrel, then you can find that in the "build it yourself" section. (you will have to also remove the gas tube which is showed in the same location)

-stabilize the barrel so it won't roll around on you when you strike the punch. I'm sure there are a million ways to do this. For me I used two wood clamps, one on each end holding the barrel just about 1.5 inches off my bench, then I stuck a small socket under the FSB tapered pins. I then adjusted the the clamps so that the barrel is resting on the socket and the clamps are holding the barrel level and parallel to the bench (not sure if this is making sense, if I had a pic it would help).

-the reason for the socket is to provide a solid support when you strike the fsb

-get a large hammer (I started out useing a standard ball peen and found out it wasn't big enough, so I moved up to a medium sized lead mallet)

-useing your large hammer and punch pin (I started mine with a steel nail set) give the pin a good smack (when i say "good smack", i mean A GOOOOOD SMACK, not some girly). This is where it's important to make sure the barrel is level and parallel and held tight!!)

-with any luck the pin will move down just a little. use your punch to tap it the rest of the way out

-move the socket to the next pin and repeat.

-it's important to note the pins exit to the same side that your shells eject from (to the right)

-i originally tried to knock the pins out by placing my FSB on top of a block of hard wood. i got one out, but the other would not move, no matter how long or how hard I hit it with the ball peen hammer. i switched to the method described above and all it took was one hit with a larger hammer and the other came right out. I felt so dumb, but i was happy it was out.

-a trick that has been mentioned here is  to heat the pins up with a small torch to help loosen them up.

I hope this helps you in some way. if I've given bad gouge, I'm sure someone will come along and correct me (or tell me I'm an idiot), either way it worked me.

Now, what are your plans for that old FSB?  I'd be interested in it if you want to sell it.

HAPPY HOLIDAYS

Gene

ps   i did not click the "SPELL CHECK" button after typing this.