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6/28/2008 10:45:09 AM EDT
Is there a standard measurement to locate the holes in the barrel for the gas block? What is this dimension?
Would this determine the length of the pipe? Does this determine whether the piece is called a pistol, carbine or rifle
How many different lengths are there?
Thanks for the help.

Forrest
6/28/2008 12:51:13 PM EDT
[#1]
I do not know the exact measurements but there are, for the 5.56, roughly 4.  Rifle, mid length, carbine, and pistol.  Each has its own relatively standardized gas port location and size, and gas tube length, but again, I do not have that information handy.  That info is located somewhere on the boards, you might check out the "build it yourself" forum and read the tacked threads, I think it is in there.  Just be aware that when you order a gas tube you need to know at what position your gas block is going to be.  
Other calibers often have their gas ports located at slightly different locations than what the 5.56 is and they may be of different diameter.  All that is determined by the designer, often through trial and error.  My .500 Phantom is done on a mid length LR-308 platform which Marty had never done before, so he drilled the gas port small and I started enlarging the gas port in .001-.003 increments until it functions.  
6/28/2008 12:55:34 PM EDT
[#2]
Thanks Big-Bore, Thats the kind of info I'm looking for. I appreciate it.

Forrest
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