FSB pins, what's the trick

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[ARCHIVED THREAD] - FSB pins, what's the trick

Posted: 3/19/2006 2:14:39 PM EDT

Hey guy's,

I ordered a FF tube for my Bushmaster but I can't seem to get the pins out without bending my punches.

I'm on my way to ruin punch number two, any suggestions would be greatly appreciated.

Thanks,
Spot

Posted: 3/19/2006 2:26:28 PM EDT

[#1]

Heat up the area. Apply Kroil. Dremel the ends of the pins dead flat and use a quality punch that's SHORT and has a dead flat face of the right diameter. FIRMLY support the barrel and FSB on
something like a large anvil, and give it a SHARP whack with a good sized hammer.

If all else fails, you're scrapping the FSB anyway so use a cutoff wheel with your Dremel and thin
it out a lot (not quite to the barrel, but as close as you dare) and then break it off with a chisel
struck at an angle.

CJ

Posted: 3/19/2006 2:28:56 PM EDT

[#2]

The pins are tapered you first need a Starter Punch. A starter punch is tapered too; the idea is you can hit this type of punch harder than a straight punch. Once the pin has started to move you then use the correct size punch to knock the pin out. make sure you are moving the pin from the smallest end. When you are looking down the barrel you should be knocking the pin from left to right.

Note: This is the reverse of most small arms pins. Most pins in the small arms world go in from left to right and out from right to left

Again the bottom line is to ensure you are knocking the pins out from the small end to the large end. Once the pin is started out they usually do not take much to get them the rest of the way out.

Good luck

Posted: 3/19/2006 4:15:45 PM EDT

[#3]

Update,.. No sucess but an update anyway.

I applied Kroil, heated, and ground them down... dern things are tight and won't budge.

It's a bushmaster and the gas tube pin came out right to left so I followed the same with these pins which I can't get out.

I'm still trying although the punch I have is warping more and more.

I don't have a starter punch..

Who makes the best set of punches for this stuff ? And are there any more tricks..

I used my large vise as the base to drive out the pins, no luck.

Spot

Posted: 3/19/2006 4:19:48 PM EDT

[#4]

Just grind down the front sight and use the gas block portion of it if it isn't ruined. Or with some careful pushing since you have the tube pin out just push it farther into the reciever then turn the tube and pull it out past the FSB and voila, you can now unscrew the barrel from your upper.

Posted: 3/19/2006 4:53:31 PM EDT

[#5]

I have the gas tube out, and the barrel removed.

What I'm trying to do here is put on a free floater tube for competition.

I just managed to destroy my best punch.

I heated the FSB around the pin under the barrel as hot as I would dare to after letting it soak in kroil for an hour or so. NO GO.

So here's my options.

1) Cut this thing off and order a new FSB from Bushy to replace it (I think the air holes were tough to line up and this is not too good a thing to do?).

2) Leave this barrel / FSB and use it on a second upper (flat top I have sitting around) and order a new barrel from Bushy for competition on the A2 upper I have.

I can't see geting the FSB off without cutting it in half at this point.

What's the likely hood I can order a new FSB from Bushy, put it on and have things work right?

Spot

Posted: 3/19/2006 5:32:38 PM EDT

[#6]

Bushmaster won't sell ian FSB, at least, to you.

They don't sell parts that require gunsmithing to install because they don't want you to
be sending them YOUR goof to be covered on THEIR warranty.

Fulton Armory will sell you the parts, though.

CJ

Posted: 3/19/2006 5:34:40 PM EDT

[#7]

Quoted:
Update,.. No sucess but an update anyway.

I applied Kroil, heated, and ground them down... dern things are tight and won't budge.

It's a bushmaster and the gas tube pin came out right to left so I followed the same with these pins which I can't get out.
I'm still trying although the punch I have is warping more and more.

I don't have a starter punch..

Who makes the best set of punches for this stuff ? And are there any more tricks..

I used my large vise as the base to drive out the pins, no luck.

Spot

the fsb pins are tapered and come out from left to right, the gas tube roll pin is not tapered and will come out either side. Intruction are about half way down this page

Posted: 3/19/2006 5:45:04 PM EDT

[#8]

I did a quick look that specific page just before I did my last round with the FSB.

Dern Bushmaster pins!

I could try to drill out the pins and replace them with new ones.

Anyone done that before.

Spot

Posted: 3/19/2006 5:52:14 PM EDT

[#9]

You can replace the pins with certain bolts but I would trust pins more. I would at this point cut the bugger off and buy a new one from fulton armory. And make it a flip-up if you want.

Posted: 3/19/2006 6:15:58 PM EDT

[#10]

I thought that getting a new FSB to match the barrel hole was some sort of vodoo magic?

Can I just do as your saying and swap it out?

The thread on FSB's said that with the old one your good, it didn't go into using a new one.

Spot

Posted: 3/19/2006 6:19:33 PM EDT

[#11]

Some barrels have special little fitting notches on them for the FSB/GB. The only way to really find out I guess would be to open her up. And it sounds like you've maimed it enough that it might move on its own while you shoot or have leaks.

Posted: 3/19/2006 6:25:09 PM EDT

[#12]

I don't think I moved the FSB on this one at all, the pins didn't give any, and I only took them down to the FSB surface.

I'm just surprised the thing is stuck so well.

Spot

Posted: 3/19/2006 6:45:04 PM EDT

[#13]

SUCSESS!

I took the broken punch and used a file to taper it down like the 2nd guy mentioned - I created a starter punch.

I put that on a 2x4 and with 2-3 sharp raps she came free.

All I have to do now is get the flash supressor off and all will be well.

It's soaking in Kroil right now.

Thanks for all the tips guys, in the end It's all of it that got me there.

Spot

Posted: 3/19/2006 7:35:18 PM EDT

[#14]

What a pain, but it's done, the Free Float tube from Bushy is on and it's looking good.

I'll most likely get some new pins to replace the one's I ground down.

Aside from ox-blue what do you guy's use for touchups to match the finish on AR's?

Thanks again for the help.

Spot

Posted: 3/20/2006 6:38:29 AM EDT

[#15]

Sorry I am late with this, but what worked for me was to get the barrel off the upper and then place a 1/2in socket directly under the pins of the FSB. I tapped it with a 5lb hammer and out it came. Prior to that i was doing the same thing that you were going through. Even thought about the dremel after a while...

Posted: 3/20/2006 7:39:26 AM EDT

[#16]

Tool

What I did on those really hard to remove ones is get two of these blocks. One block is sold and works for either removing or installing the pins.

I sandwich the FSB and clamp it down to a bench with a c-clamp. Get a punch or use my 10 ton press and push the pins out. Now you have a guide so the punch will not fall off the pin and the FSB is in a cradle and clamped. The pin pops through the hole in the bottom block.
Sometimes I put the barrel or upper in the freezer before I hit the pins and I do juice them up for a-while first

Posted: 3/20/2006 9:17:20 AM EDT

[#17]

Quoted:
Tool

What I did on those really hard to remove ones is get two of these blocks. One block is sold and works for either removing or installing the pins.

I sandwich the FSB and clamp it down to a bench with a c-clamp. Get a punch or use my 10 ton press and push the pins out. Now you have a guide so the punch will not fall off the pin and the FSB is in a cradle and clamped. The pin pops through the hole in the bottom block.
Sometimes I put the barrel or upper in the freezer before I hit the pins and I do juice them up for a-while first

That's a neat tool/fixture. Question, is there any interferrence with the handgaurd cap?

Posted: 3/20/2006 9:21:00 AM EDT

[#18]

get craftsman punches. easily replaced when bend or broken!

Posted: 3/20/2006 11:28:28 AM EDT

[#19]

Quoted:
Quoted:
Tool

What I did on those really hard to remove ones is get two of these blocks. One block is sold and works for either removing or installing the pins.

I sandwich the FSB and clamp it down to a bench with a c-clamp. Get a punch or use my 10 ton press and push the pins out. Now you have a guide so the punch will not fall off the pin and the FSB is in a cradle and clamped. The pin pops through the hole in the bottom block.
Sometimes I put the barrel or upper in the freezer before I hit the pins and I do juice them up for a-while first

That's a neat tool/fixture. Question, is there any interferrence with the handgaurd cap?

Called Brownells myself. No interference, Tool is on order.

Thanks

Posted: 3/20/2006 2:28:13 PM EDT

[#20]

There is a place for the cap to fit into. If you are going to put a free float tube on you are going to have a problem with the tool. There is not enough clearance for certain float hand guards. You need to hope that the float tube can be put back far enough to clear the tube. Then you can screw it forward and lock it into place.

Hope you understand what I mean.

I almost forgot abut this one also. I have not used it or seen it in person, but adco has good Stuff

Another one

Posted: 3/20/2006 4:00:52 PM EDT

[#21]

Both tools are pretty cool.

Craftsman punches..! why didn't I think of that.

Barrel clamps /vise is on my list also for removing the flash surpressor.

Spot

[ARCHIVED THREAD] - FSB pins, what's the trick

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