I need to take off a front sight base to install a free float tube..
Do you just have punch out the two pins on the FSB to get it off??
Thanks

yes. remember to remove the FH before

anyway, read this
www.ar15.com/forums/topic.html?b=3&f=4&t=226782

Preparation is usually the key. To be on the safe side, thoroughly soak the two taper pins with Kroil overnight. When the time comes to drive them out, fully support the front sight base. You want the taper pins to absorb all the impact. Brownells sells an AR-15 front sight bench block (part #080-000-252) for $34.97 if you want to spend the money. Wood will work as a support, but if you have a friend's help, your best bet is to put a 4MM socket under the taper pin. It'll support the front sight base, and when you drive the pin out, it'll go down into the socket. Use a 3/32" nail set (found at Lowe's etc.) and a hammer around 16 ounces or so. Give them a couple of good, hard whacks (you don't want to pussyfoot around or you'll just mushroom the pins.) You'll want to drive them out from left to right (the same direction that your takedown pins pull out.) Once they are broke loose, use a 1/8" pin punch to tap them completely out.

Quoted: Preparation is usually the key. To be on the safe side, thoroughly soak the two taper pins with Kroil overnight. When the time comes to drive them out, fully support the front sight base. You want the taper pins to absorb all the impact. Brownells sells an AR-15 front sight bench block (part #080-000-252) for $34.97 if you want to spend the money. Wood will work as a support, but if you have a friend's help, your best bet is to put a 4MM socket under the taper pin. It'll support the front sight base, and when you drive the pin out, it'll go down into the socket. Use a 3/32" nail set (found at Lowe's etc.) and a hammer around 16 ounces or so. Give them a couple of good, hard whacks (you don't want to pussyfoot around or you'll just mushroom the pins.) You'll want to drive them out from left to right (the same direction that your takedown pins pull out.) Once they are broke loose, use a 1/8" pin punch to tap them completely out.

+1 - that socket trick, it is the only way to go unless you have a press.  With the socket over the pin directly under the FSB on the bench the amount of energy you are able to transfer directly to the pin is what makes this so easy....

i also found that heating the FSB a little with a MAPP gas torch helps expand the FSB and make it a little looser. just not to much heat because then the pins starts to expand as well.

never heard of the socket trick but i like it.

And don't forget the gas tube pin BEFORE you try to remove the FSB!

And don't forget the gas tube pin BEFORE you try to remove the FSB!

I just leave that sucke in there and take the entire unit out at the same time.

I got it!! Thanks for the help guys..

Can someone illustrate the socket trick?  I have had a long day and a couple beers so I can't really picture it?..,.

Quoted: Can someone illustrate the socket trick?  I have had a long day and a couple beers so I can't really picture it?..,.

take the upper off the rifle

take a socket with a small diamater that is just big enough to fit over the head of the taper pin without obstructing it - like fiting a socket over a spark plug. Once you pick out the socket that just fits over the taper pin set it upright on the bench or block of wood.

Now take your upper or barrel assembly and line the large head of the taper pin up with the socket sitting on the bench and seat the FSB onto the socket sticking up so the taper pin is shrouded by the socket.  

now you have the weight of the upper or barrel assembly resting solely on the socket which is on the bench or block of wood.  A friend holding the assembly for you while you line it up and set it down will help.

Once the unit is resting on the socket and the taper pin head is lined up with the small diamater socket take a proper punch and hammer and WHACK or WHACK WHACK and the taper pin will disappear as you just drove it out of the FSB and into the socket sitting on the bench.  

Line up the other taper pin with the socket and WHACKOLA.  A very smart tap well placed should drive the taper pin straight out.....I went 2/2 on my last project.  FSB and pins are very usable even for a scratch free safe queen if somebody needed them one day....

the next question is....

Will it index when putting it back on?  I'd rather use a one piece FF tube on my next build, taking the FSB off doesn't worry me... putting it back on does.

the slots in the barrel guarantee it will mount back on properly.  

You have got to use the same sight base that came with the barrel though if you are going to use taper pins in the taper pin notches in the barrel.  When the FSB and barrel were pinned together the first time at the factory they were indexed in a jig and the machine drilled the taper pin holes through the FSB and barrel in one shot.  

ETA; after market fli ups and low profile gas blocks clamp on or use set screws so the indexing is a function of lining it up and clamping it down.....

Quoted: the slots in the barrel guarantee it will mount back on properly.   You have got to use the same sight base that came with the barrel though if you are going to use taper pins in the taper pin notches in the barrel.  When the FSB and barrel were pinned together the first time at the factory they were indexed in a jig and the machine drilled the taper pin holes through the FSB and barrel in one shot.   ETA; after market fli ups and low profile gas blocks clamp on or use set screws so the indexing is a function of lining it up and clamping it down.....

Thanks SamColt....   exactly what I needed, and why I continue to spend time in the forums.  I though that there might be such slots, but wasn't certain.  

Now it's off to order the FF tube.

When I took one off I simply installed the gas tube first and backed the FSB back on the barrel using the gas tube as a level to keep it straight.