AR Front Sight Base Pins

[Flat Broke]

Last week I started stripping my brand new CMMG upper in preparation for a customized free float tube install. Unfortunately, I didn't get very far because I was a little concerned about how much force was required to remove the pins that secure the front sight base/gas block pins. After examining the pins, it looks like they went in right to left. The exposed end on the right side looked to have a visible taper and rounded head. So I tried using a punch to push them out from the left side. I had the barrel supported on two pieces of wood as illustrated on AR15.com, but after a couple of good whacks, it looked like the end of the pin was just mushrooming/flattening and not really moving. No there was nothing under the opposite side of the pin that would cause resistance. I was busy last week and just put the project asside until I got back from the Central Coast.

I wanted to bang out the machining on the free float tube this weekend and that means I need that sight base off before I can do any test fitting/torquing to index everything before I start making cuts on the mill. How hard should I have to hit these pins to drive them out? Any other tips that might facilitate the process?

Thanks in advance,
Chris

[supersonic]

>RIGHT=OUT / <LEFT= IN A quality punch (STARRETT) + 2-3 good, solid "whacks" is all it should take. This tool makes it MUCH easier, too: http://www.brownells.com/aspx/ns/sto...0BENCH%20BLOCK

Hope that helped you!
Scott

[ar15barrels]

If they don't come out with a couple good hits, STOP before you mash them.
Oops, looks like it's too late.
Now you are screwed pretty good...

I have a press fixture which gets them out without smashing them.
Bring the barrel over...

[supersonic]

If they don't come out with a couple good hits, STOP before you mash them.
Oops, looks like it's too late.
Now you are screwed pretty good...

I have a press fixture which gets them out without smashing them.
Bring the barrel over...

That's a cool alternative to the normal method.
But all that work to fabricate your own FSB taper pin jig, and you let it RUST???????!!!!!!!!!!!

To OP: if you have some WD-40 around (I definately prefer KROIL, though), put several drops around the circumferance of the pins (on left side), let it sit on its side for a few hours. That should do it. If you've "mushroomed" too much pin, you may have to get out the Dremel!!!!!

[ar15barrels]

That's a cool alternative to the normal method.
But all that work to fabricate your own FSB taper pin jig, and you let it RUST???????!!!!!!!!!!!

That's two generations old.
I stopped using that one at least a year ago.
I live less than 2 miles from the beach.
Everything rusts in my shop.

[Flat Broke]

Thanks for the tips guys. The material just started to flatten a bit so I stopped, so I don't think it's FUBAR yet.

Randall, thanks for posting pics of the jig. If soaking it and giving it another go doesn't work out. I can duplicate that jig pretty quickly.

Hopefully I'll have some pics of my completed build by the end of the weekend.

Chris

[ar15barrels]

thanks for posting pics of the jig. If soaking it and giving it another go doesn't work out. I can duplicate that jig pretty quickly.

Don't duplicate it.
I have a better one now that's still easy to make.

[supersonic]

That's two generations old.
I stopped using that one at least a year ago.
I live less than 2 miles from the beach.
Everything rusts in my shop.

"WAAAAH! I live too close to the beach!!! WAAAH!!!!