I have a Bushmaster Dissy.  I would like to install a LaRue 12.0 forend.  Any issues with the carbine length gas block?  Can I follow the instructions in the tacked thread above?

Thanks

The tube will not clear your present gas block.  It would have to be replaced with the LaRue low profile gas block.  The back of the LaRue tube has an opening that only the LaRue gas block fits through.  Anything bigger won't fit.

DT.

Thanks.

I have not purchased the LaRue yet.  Is there a forend option that does not require a gas block change?

Mark

Mongo- why can't he use a LaRue 12.0?  How big is that gas block on a dissy?  Couldn't he grind off the squarish shoulders up top so it's just as narrow as the gas tube and be ok?  it's basically an A2 gas block cut off right above the gas tube, right?  if it's just the extra width, i'm sure a dremel could take that off quick enough...

Quoted: Mongo- why can't he use a LaRue 12.0?  How big is that gas block on a dissy?  Couldn't he grind off the squarish shoulders up top so it's just as narrow as the gas tube and be ok?  it's basically an A2 gas block cut off right above the gas tube, right?  if it's just the extra width, i'm sure a dremel could take that off quick enough...

Like I said, the opening on the rear of the LaRue is shaped such that the only gas block it will slip over is the LaRue low profile.  There are pics floating around somewhere, but I don't have them.

how about the SAMSON ? might be easier for you.

I'll take Mongo's word for it- the DD has only about a 1/4" space for the gas tube to travel through and therefore anything that the gas tube attaches to (the gas block) will have to be very very small.  

Quoted: I'll take Mongo's word for it- the DD has only about a 1/4" space for the gas tube to travel through and therefore anything that the gas tube attaches to (the gas block) will have to be very very small.

Mongo is right.  But, you should take my word for something also.  I've built a Bushmaster Dissy with a 12.0 LaRue.

16", M4 profile, carbine gas system Dissy bbl from Bushmaster:   The "hacked" gas block can stay.  Although it has to be removed in order to replace the standard bbl nut with the LaRue bbl nut, you can put it right back.  This option appealed to me the most because I did'nt have to buy another gas block and I knew the origional one would fit right back on with out any problems.

You'll need a grinder.  Not a real big one, but a cutting wheel on a dremmel won't work either.  A stone on a dremmel may.  I used a 3" stone on an air powered 90 degree angle head MAC.

Grinding:  You'll need to shave the gas block down just a bit to give yourself a wee more installation clearance.  Remember..."Just a bit".  Then you'll have to shave off the "webs" on the upper portion of the gas block sides.  There are four "webs".  You won't need 'em anyway because you are no longer supporting a sight tower.

Coloring:  I used a $6 flat black paint marker from a craft store to re-blacken the gas block.  Nothing fancy.  You won't even notice the slight contrast in the different blacks.  Remember, that gas block is going to be under your new 12.0 LaRue rail.

It works!  Your biggest problem will be removing the taper pins that hold the gas blocks on.  The front pins came out real easy.  The back gas block pins were a real ass ache, but I got the job done.

A personal note:  I feel this is the best way.  It will give you the most "hands on" in customizing your rifle.  It is also the cheapest.

Thanks for your replies!  

Mark