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3/22/2005 4:50:55 PM EDT
Does assembling a 9mm upper require headspacing?
3/22/2005 5:12:58 PM EDT
[#1]
Nope.  The headspacing is taken care of when the barrel extension is installed.  You just put it in the upper, tighten it down, and go.
3/24/2005 7:14:01 PM EDT
[#2]
Which one is ya talking about.. Colt or Oly style?  

There isn't a barrel extension with 9millies... but nonetheless.... no headspacing required for brand new mfg 9mm.

~D~

SNS
3/25/2005 8:33:26 AM EDT
[#3]
9mm Colt pattern is chambered right into the end of the barrel, but you should at least have a look to verify....  I had a 9mm barrel cut from blank, and the fella that made it chambered it too deep,  to the tune of .025" too deep...  the fire pin lost all it energy traveling the distance.

I had the barrel set back, so the case sits out .130", and with the .125" pocket on the bolt, I have a .005 air gap between front face of bolt to the barrel face so dirt can collect and be squeezed out and not strike barrel face until chamber is empty.
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