Drill,pin & weld flash hider

abj128 · Apr 24, 2012

I have a question.Iam into my first ar build (going grate).I ordered an upper
from BCM 14.5 standard flash hider i thihk i like it the way it is.But to be
legal it needs to be pined & welded.I got a price from a local gunsmith
$100.00 Being a machinist/tool maker i have the know how to do this.
But i cant seem to find the law as far as what pin diameter,hard or soft pin?
Hope someone can help me.

MachIVshooter · Apr 24, 2012

Pin diameter does not matter. The requirement is that it take more than 200 ft/lbs torque to break the pin/weld. Because of this, I would probably go with at least a 3/16" tool steel pin, and make sure it's got enough bite on the barrel.

Gimmered · Apr 24, 2012

I've seen them use a piece of drill bit to meet the requirements.

DoubleTapDrew · Apr 24, 2012

Did you already get the upper from BCM? They'll add one of their A2X flash hiders (1.5" A2 style) permanently attached for $45, which is $10 more than the flash hider goes for. Pretty good deal IMO.

abj128 · Apr 24, 2012

Yes i have the BMC upper with flash hider installed but not pined.
I did not know this was an option,maybe they wanted me to
make the choice of another flash hider before pining.
Looks like i will do it myself with the help from everyone on THR.
I will let you all know how it turns out.

fatcat4620 · Apr 24, 2012

You sound like you know what to do, just not sure how far to go. Attach the flash hider in a way that removing it with hand tools would destroy the barrel our make the right inoperable.

HankB · Apr 24, 2012

Just as an FYI . . . at least some commercial operations that blind pin the suppressor in place just weld it over for about half the pin's diameter, maybe a little more; that way anyone who's interested can see there's a pin there, and verify there IS a weld. Otherwise if it's welded over completely and then smoothed and refinished, the pin "disappears."

madcratebuilder · Apr 25, 2012

I use .062 drill rod for pins. Factory pin jobs I remove are .062 pins on the A2 FH. Silver solder meets requirements also.

Drill,pin & weld flash hider

abj128

Member

MachIVshooter

Member

Gimmered

Member

DoubleTapDrew

Member

abj128

Member

fatcat4620

Member

HankB

Member

madcratebuilder

Member

Similar threads