Ok, why is this damned thing not fitting under my Samson rail?

It says, "For use with railed foreends".  This thing is a pig!

Ah crap, nevermind.  I guess you have to have the "Specter" gas block.

F'in YHM could not have made that more confusing!  Why would you sell a "low profile" gas block that doesnt fit under a rail system?

Quoted: Ah crap, nevermind.  I guess you have to have the "Specter" gas block. F'in YHM could not have made that more confusing!  Why would you sell a "low profile" gas block that doesnt fit under a rail system?

No, that one will fit under a yankee hill tube, either the customizable or the railed one. It must be the Samson tube, 'cos there's at least 1/8" of clearance looking at my railed forend.  Here, see for yourself:


I've got both the low profile and the specter...when all is said and done, they're pretty much the same height.  

Measure the inside diameter of the tube...the YHM is 2.815.  Also, make sure nothing is sticking into the tube from the top or bottom.  

MP,

I might shed some light on this.  I have a YHM and DD quad rails and the YHM has a much larger inside diameter than the DD.  The last Sampson rail I saw was like the DD.

I feel the YHM low profile is desidned to fit inside of a YHM quad.

BTW, the outside diameter of the YHM rail is much bigger, almost feels like an R-4 handguard.

Just my thoughts.

Ooopps!!! My buddy Fenian beat me to the punch, just read what he wrote. Anyway we are thinking alike.  

77Bronc

Quoted: ...No, that one will fit under a yankee hill tube, either the customizable or the railed one. It must be the Samson tube, 'cos there's at least 1/8" of clearance looking at my railed forend.  Here, see for yourself: img.villagephotos.com/p/2003-5/188491/lowprofile1.jpg I've got both the low profile and the specter...when all is said and done, they're pretty much the same height.   Measure the inside diameter of the tube...the YHM is 2.815.  Also, make sure nothing is sticking into the tube from the top or bottom.

Could I kindly ask you to show a picture of the setup from the side? I'm contemplating the same exact setup as yours and would like to see how it looks. Is yours a 16 inch barrel?

Sorry I didn't see this sooner, but I've been out of town.  Here's a shot of the upper...16" Model 1 barrel, everything else is YHM.

I have no experience with the sampson rails, never built one up, but I have done just about all the other major makers.

Larue and Daniel Defense are much smaller 'clearance diameters' inside the tube, allowing a proper picatinny spec on the rails without growing the handguard as large when you put the big rail covers on them.
YHM have a much larger 'clearance diameter' and YHM's gas block designs reflect this.

Here is a LaRue rail and a 0.940" diameter low profile (but still too wide) gas block that did not fit either.
We were trying to use a 13.2" handguard to cover the gas block, but ended up with the 12.0 instead.


This is exactly why LaRue and PRI have gas blocks with a really SLIM profile (slim as-in NARROW, not just LOW), but there is still no way to put a 0.940" gas block under some handguards.



Randall Rausch
www.ar15barrels.com