A2 Front Post Taper Pin Removal Issues (HELP)

[Hammer285]

I am having a bear of a time getting the taper pins out of an A2 front post. I do not need the sight, and am replacing it for low profile adjustable gas block to properly gas a new suppressor. 

What I have done so far:

• Hand guard is off.
• Brake removed.
• Gas tube roll pin is out.
• Gas tube removed.
• Barrel Removed from upper.
• Measured taper pins on both sides to verify the correct side to slam (hitting the 0.12 side v 0.14 side)

I started hammering away with the punches and the pins didn't budge. I noticed both sides of the taper pins were a little mushroomed, so I shaved down one to cut that tip off and went back to hammer. 

I have had absolutely zero movement or luck. I have broken two steel pins at this point and am giving up.

I really would prefer not to have to buy the Brownell's A2 sight pin block for this as I'm just tossing the sight. 

I have watched numerous videos of people doing this, some make it look easy, some hard, but none impossible. Starting to think there is something wrong.

Does anyone have any advice, tips or ways to get this thing off without damaging the barrel? Hammer the sight off, cut it with a small angle grinder/blade, etc.?

If there is a gunsmith out there willing to do this for some $$, I would gladly ship it out with a pre-paid return box to get this done and turned around fast. 

 

[Garufa]

I did this one time.  Never again.  Those things are in there tight.  After the initial beating had little to no effect, I started putting Kroil on the pins and letting it soak in.  Did that over several days along with a few taps using a steel punch.  Eventually they broke free enough to drive out.

After all that work I ended up putting it back on a couple of years later, lol.

Edited August 1, 2020 by Garufa

[maroonandwhite]

Yeah put some penetrating oil in there. It took mine a few VERY solid hits to break it free. 

[gregintenn]

Hacksaw, grinder, bigger hammer...it WILL come off!

[maroonandwhite]

I will also add that mine didn’t move at all.... until they did. Once you get it to move that little bit, the rest is easy. I believe I used some combination of 2x4’s as a makeshift jig. You have to make sure that every bit of your hammer energy is making it to that pin. If it’s rocking or moving at all I doubt you’ll ever get it out without grinding. 

[RED333]

11 hours ago, gregintenn said:

Hacksaw, grinder, bigger hammer...it WILL come off!

13 hours ago, Hammer285 said:

I'm just tossing the sight. 

2 options

1st is Greg's above

2nd is buy a barrell

Edited August 2, 2020 by RED333
Because I can

[leroy]

Doya reckon that the pins and holes are tapered..? Kroil em good and try ta drive from the other side...

leroy

[Hammer285]

On 8/2/2020 at 5:59 AM, RED333 said:

2 options

1st is Greg's above

2nd is buy a barrell

Yeah, I'm going to keep giving it a go, but did just buy a San Tan Tactical barrel in case it doesn't work. 

https://www.santantactical.com/stt-ar15-barrel-223-10

[RED333]

45 minutes ago, Hammer285 said:

Yeah, I'm going to keep giving it a go, but did just buy a San Tan Tactical barrel in case it doesn't work. 

https://www.santantactical.com/stt-ar15-barrel-223-10

Did you try heat?

[peejman]

What they said... Kroll, heat, and patience.  If they've been peened in place, they'll be tough to get out. 

[Capbyrd]

12 hours ago, Hammer285 said:

Yeah, I'm going to keep giving it a go, but did just buy a San Tan Tactical barrel in case it doesn't work. 

https://www.santantactical.com/stt-ar15-barrel-223-10

If you end up replacing the barrel, let me know what you want for it.  


Regardless, here is a video on taper pins.  The key is to use a punch larger than the pin head.  You put the punch over about half of the pin head and give it a good solid whack.  That frees it and then you can move to an appropriately sized punch to remove them the rest of the way. 
 

 

 

 

[ken_mays]

I use a BFH (big freaking hammer) and a very short starter punch.  Get the front sight block in a big vise as close as possible to the taper pins and whale away.

[Dave Keenom]

Hydrologic press or,

air hammer and the pointed bit

I have used the air hammer method a few times.  

Secure barrel in vise or on table with a block and bip it with the hammer. 

Like others have said, just get it to move then use normal punch and manual hammer method. 

[btq96r]

I'd have to dig for the thread, but once upon a time a member who I don't see post much anymore helped me get the FSP off my AR upper using his blow torch to heat it up and make the pins easier to pop out.

[TGO David]

They are called taper pins for a reason.  One end is larger than the other.  They only go in and go out one way. 

 

Heat helps.  A short starter punch helps even more.  An armorer's block designed to hold the barrel and sight fixture flat and secure while you beat on them helps just as much.  They will come out, but they are designed NOT to come out easily.  That's their point. 

 

Depending on how badly the narrow end of the pins have been mangled in the current efforts to free that A2 sight and gas block from the barrel, you may need to have someone with a drill press and armorer's block help bore out the part of the narrow end that is captured in the gas block so that it can be driven free.

 

[TGO David]

I will add... the way the PINS should be oriented is as follows on an AR in standard config with the ejection port toward the right-hand side of the user.
 

INSTALL:  Drive IN  from the ejection port side (right side) of the rifle

REMOVE: Drive OUT from the the bolt release side (left side) of the rifle.

[Omega]

Yup, my guess would be taper pins.  I had the same issue with my S&W gas block, busted a few punches before I figured it out.

[btq96r]

2 hours ago, TGO David said:

They are called taper pins for a reason.  One end is larger than the other.  They only go in and go out one way. 

[TGO David]

5 hours ago, btq96r said:

I've been there.  My knowledge is gained from experience, albeit not on an AR.  Taper pins are used in other machinery and I've buggered them up removing them from the spindles that hold pulleys onto electric motors.