Seriously BCM? What do you use for FSB pins? Or: Never invade Russia in Winter.

[titsonritz]

This is the truth.

https://en.wikipedia.org/wiki/Winter_War

Can't bring up the Winter War without bringing up Simo Häyhä.

[scottryan]

The correct approach to this problem is to sell off the BCM barrel intact and buy a barrel from a reputable company that sells it with a low profile gas block pinned in place (DD, Noveske, KAC) etc.

If you have to buy a whole new upper, so be it.

The orange "hockey puck" thing that Brownells sells is worthless.

[Iraqgunz]

I don't think he is putting a rail and low pro on it. He is trying to install a rail on the existing upper.

The correct approach to this problem is to sell off the BCM barrel intact and buy a barrel from a reputable company that sells it with a low profile gas block pinned in place (DD, Noveske, KAC) etc.

If you have to buy a whole new upper, so be it.

The orange "hockey puck" thing that Brownells sells is worthless.

[khc3]

If the drill drifts off something domed, like a rivit or the end of a tapered pin, stop because the drill will drift off every time. When that happens, you have two options. Either flatten the top of the dome with a file, or center punch it. Once the dome has been flattened or center punched, start with a center drill

You can also use an appropriately sized center cutting end mill to flatten domed pins.

[markm]

The orange "hockey puck" thing that Brownells sells is worthless.

Completely AGREE. I own one, and it's a useless piece of shit for tightly fitting pins. WORTHLESS.

[jpmuscle]

Did anyone mention using direct heat yet? Seems straightforward enough but I haven't messed around with to many FSB assemblies over the years, fortunately or unfortunately perhaps.

[markm]

One option that I've found to work on some of these Paul Bunyan-esque over seated taper pins (Colt, BCM, Sionics) is to clamp the bayo stud into a solid vise. Dicking around with anything soft or flexible like brownell's shit block is a waste of time. The bayo stud may get a little chingered up, but nothing compared to the OP's horrific pic.

[twm134]

A big hammer (3 to 4 pounds), a concrete floor, good steel punches, and brace the barrel with wood blocks and rags to protect it. This has always worked for me and on several barrels/blocks. Brace the barrel and block well and hit it with a big hammer and it will break loose.

I agree the flexible block from Brownells is a waste of time and money.

[kwelz]

Sorry I haven't gotten back to this today. Been a long one. Showed 9 houses and fired a contractor! Oh and I made it by the Gun shop, where I am happy to say I found vindication!

Did we get the pin out? Nope. Not even close. Concrete floor and 3 of us got the pin to move about 1/16 of an inch. I want to know when BCM hired Hafþór Björnsson to install these things. Don't get me wrong, it makes me want to see the factory even more. But tell him to take it easy ok Paul?

All Joking aside we did work on this for a good 30 minutes. Once we applied heat we got it to move a tiny bit as I mentioned above. However that was all the movement there was. Finally we gave up. Since the FSB was already messed up we decided just to cut it off.

Here is the section with the in. You can see how much we were able to get it to move.

20170119_223213.jpg

So I am in the market for a .625 FSB or Gas block if anyone has one.

Oh the up side I did walk out of the shop with a Saint. Now THOSE pins I was able to get out and install that rail. The really sad part? I don't think I like it.... Yeah. Where did I put my Woodford?

[MistWolf]

It used to be that BCM sold their uppers with the FSB pins installed with only finger pressure