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Teddydog
January 11, 2009, 21:25
Need help/confirmation in selecting a LS for my FAL build (my first).

Using the Forster H.S. gauges and pin gauges spaced .002, targeting NATO headspace specs. I found that the bolt would close using very light pressure and a .261 pin gauge. Using the .263, the bolt would NOT close at all (very far out, in fact). Extrapolating, then the .262 would likely not close either or close with heavy pressure.

So, take .262, add .001 for setback and subtract .002 for using the Forster gauge and I'm left with a target LS of 0.261.

Does this sound right? Too bad my current LS is 0.258.

Thanks!

Rob

jbgw
January 11, 2009, 21:30
These instructions work well if you have not read them
http://www.falfiles.com/forums/showthread.php?s=&threadid=119640

shlomo
January 11, 2009, 21:34
Originally posted by jbgw
These instructions work well if you have not read them
http://www.falfiles.com/forums/showthread.php?s=&threadid=119640

Does that mean that they don't work well if you have read them?

L Haney
January 11, 2009, 21:54
Originally posted by shlomo


Does that mean that they don't work well if you have read them?

Bad Schlomo! This is not the thread for existential questions. Or is it? Was it once? Never mind, I've got other imponderables to ponder upon. As you were. :p

shlomo
January 11, 2009, 22:17
And I wonder why nobody likes me.

jbgw
January 11, 2009, 22:26
I was actually hoping that the poor fellow would get to have a functional rifle. Boy was I sorely misguided.

shlomo
January 11, 2009, 22:42
Sorry.

Misguiding can produce soreness.

shlomo
January 11, 2009, 23:33
Teddydog,

Sorry for my flight of fancy. Sometimes I can't make the voices be quiet.

I don't use the particular method you are describing, so I can't comment on it. After reading the link that was kindly provided by jbgw, and doublechecking your arithmetic, let us know if you have further questions, or if you need a particular size shoulder.

There're a lot of 'em floating around among the folks on this board, and I'll bet somebody will surface who can ease your pain.

:whiskey:

Teddydog
January 12, 2009, 00:26
Actually, that was NOT the one I used for my first test. I was following a guide that I SWEAR said to use the NO GO for setting the headspace.

I followed the linked guide and came up with the following, using the Forster GO gauge:

Bolt closed and locked easily on a .265 pin and would NOT come close to locking using a .267. Extrapolating, it looks like .266 is the pin that would just close on the GO gauge.

So the math: 0.266 pin, -0.002 to go midrange on the HS and +0.001 for setback gives me a 0.265 LS.

Thanks for the link and the re-point. My initial finding using the NO GO probably would have given me a rifle that was too tight for a lot of ammo.

Rob

shlomo
January 12, 2009, 00:50
Actually, it would have been too loose, Lautrec.
The "NO-GO" gauge is NOT supposed to fit in a chamber that is within headspace tolerance. It is roughly five or six thou over the minimum headspace dimension, and if the gun closes on it, it means the gun's over tolerance.

Not closing on the "GO" gauge means the gun is too tight.

Think of it this way: for a chamber in spec, the GO should go, and the NO GO should not.

Teddydog
January 12, 2009, 01:47
Yeah, I know about the GO and NO GO gauges.

I was thinking about the size of the locking shoulder as keeping the bolt FURTHER AWAY from the barrel when the size increased. However, I just realized that the locking block on the bolt drops down in FRONT of the LS, not behind, so a larger size LS pushes the bolt CLOSER to the barrel, making for tighter headspace. Duh.

Thanks.

Rob

jbgw
January 12, 2009, 12:27
I use the no go to double check on myself. If the bolt does not close on your .267 pin then you are set. Never can be too careful.
Unless Shlomo says otherwise(guy)

shlomo
January 12, 2009, 19:40
:devil: :rofl: