Have you ever read Duncan Long's book "AR15/M16: A Practical Guide"? I noticed a potentially dangerous error in it, one which apparently carried over into his more recent "The Complete AR15/M16 Sourcebook"
Turn with me now to page 143 of "Sourcebook".
He writes-(read carefully)
"The most ideal combination is to have a barrel/bolt combination that accepts the GO and FIELD gauge, but not the NO-GO gauge..."
This is right after he gets done saying-
"To determine if a rifle with excessive headspace(one that accepted the NO-GO gauge) is safe, use the FIELD gauge. If the bolt turns on this gauge, then do not ever fire a round in this barrel. To do so would be extremely dangerous."
To recap-
In real life-
It should take the GO gauge...
It shouldn't take the NO-GO gauge, but it might be safe, use FIELD to check. If it doesn't close on FIELD, use bbl, just not w/ maximum loads.
It REALLY shouldn't take the FIELD gauge!
SO WHY DOES DUNCAN'S BOOK SAY IT SHOULD CLOSE ON THE FIELD GAUGE!!!!!????? (all HANGFIRE'S caps are belong to us)
This is a REEEEALLY dangerous Typo/error. Imagine the dude, who, in good faith, buys a bbl with excessive headspace, closes it on the GO(it goes, of course) then closes it on the oversized FIELD gauge(it goes) dude takes new rifle to range, and Dean Speir(Just visiting from the Gun Zone [xx(] ) has another Kb! of the week to write about, we have one less AR enthusiast in the world.
Just be aware-tell any friends who have either book, so they dont lose their hands and their gun(or maybe more) [:(]
Juggernaut