Gas Tube Roll Pin problem....

[wayfarin'stranger]

I have an DPMS M4 that I want to swap the A1 Reciever for an A4 Flat-Top. I understand how to remove the barrel and all that, but the gas tube roll pin on the FSB has me a little confused.

1. Is this supposed to be a solid roll pin like the rest on the FSB?

--Mine is hollow and I'm a little hesitant to hammer a punch in there without knowing the exact diameter punch to use if the thing is indeed hollow. I can't tell for sure because it just looks like a hole that runs all the way through the gas tube.

[Snake RAH]

Roll pins are thin sheets of metal rolled into a pin, and cut to length. The roll pin which keeps the gas tube in place on your front sight base will require a 1/16" punch (actually, I think it is 5/64", but you can't find a 5/64" punch easily).

The other pins on your front sight base are either taper pins or metal dowels (no taper). Since it is DPMS, I would say they are probably taper pins.