Hi everyone!  Been a few years since ive been here.  I have been looking for an AR180b firing pin as a spare for a while now.  Should of gotten one when i bought the rifle 13 years ago.  Well, there is not much out there.  Here is a pic of the major suspects:

The top one is the original 180b pin.  Notice the slight bevel on the rear of the collar used to hold the pin in the bolt carrier by a pin.
The one underneath it is from firingpins.com.  it has a nearly 45 degree angle on the rear of the collar. That angle makes the pin push down on the bolt interior and makes it a bit rough as it slides in and out of the carrier.  I thought wtf at that design then Josh at stormwerks.com sent me this pic of an original AR18 pin:

Part 2:
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Notice that that bevel is nearly the same?  So go figure on my opinion of the firingpins.com pin.
 The last pin in the pic with the 3 pins is a titanium one fron Davidson defense.  Its an AR18 pin, but supposed to be backward compatable with the AR180/b.  It does not have the angle on the collar like the original 18 pin.  It also does not fit into the bolt firing pin hole.  The firingpins.com pin has a tip diameter of .068, and when using my caliper on that tip i agree. When i try the caliper on the davidson pin it is larger than that and will not fit.  I have access to 4 of the davidson pins and they are all oversize.  Won't fit in my sterling AR180 bolt either.  I'm still negotiating with the vendor over the return of those.  Point is no one seems to have a completly correct replacement pin.  There is a Caniadian company that is supposed to release bolts and bolt parts(rangewarrioraccesories.com) as soon as batfe gives them an answer over the shipment to the usa of those components.  Hope this helps those who still shoot the AR18/180/180b rifles.