Hi,
Sorry my question maybe noobish but I am unsure of how to proceed.  My rifle has a tube handguard w/o any rails.  Presently I have a carbine lengh gas system with a low profile block under then handguard.  I am thinking of adding:

A) Quad or tri rails mounted on the barrel, would put a flip up front sight on the top rail.
B) Flip up front sight, barrel mounted

Questions:
Every part that fits the bill I have seen fills a double duty role as also being a gas block.  Since I already have a gasblock it seems dumb and redundant  to use one of these parts, having two gas blocks... added unnecessary weight.  

1) Is there a product that fits this need that is lightweight and not redundant?
2) would I be better off removing the current gas block and replacing it with one of the products mentioned above?  If I did this I would need a longer gas tube.  My barrel is 16" so I would then have a rifle length (or longer, the sight would be very near the muzzle) gas system replacing the carbine length system in place.  Would this even work?
3) Should I scrap the barrel mounted type of products and look into an alternative? Suggestions?

Thanks for your help.

 

I figured that this maybe the case (changing the gas system complicates things much further).  Putting a rail on my HG (which accepts modular rail sections) and throwing a flip up on there will look really bad (its an armalite free float tube which is really thick/wide) Another concern is the height, again due to the size/profile of the tube. While the A2 front sight/block would work, this sight would be a BUIS / cowitness (primary optic is Red Dot).  Additionally I would get one with a bottom rail for a tac light.  So it seems like the most practical option is flip up front sight gas block in front of the HG.

Thanks for your input. At this point I am exploring options, and the more that I think about it I like how light weight my rifle is at the moment.  I like the YHM-9835A http://www.brownells.com/rifle-parts/gas-system-parts/gas-blocks/ar-15-m16-clamp-on-front-sight-gas-block-prod21446.aspx
But at 220g is a bit more weight than I am willing to add.  Something that about 1/2 that weight (4oz ish) would be a  better option but I think that may need to sacrifice the bottom rail in that case.

 

I have a 12 inch free float tube style Armalite handguard on these presently.

Pictures always help.   Change your hand guard.

if you could find a cheap used set screw type fsb you could mount it closer to the muzzle,
sort of the way they mount the on faux dissapators. it would change no function other than just
adding a sight.

more expensive, change out the barrel nut / handguard with a quad rail, and then buy a front sight.

Change your hand guard.


Most of the tubular ones (with the YHM style lock ring) are junk anyway.  Best bang for buck would be either a Centurion Arms or BCM hand guard.

If your Amalite tube accepts a rail the rail will probably be at the standard height.
So any rail mount flip up for free float tubes should work.
The YHM clamp on gas block/flip sights work fine, but you will have to cut down the existing tube to fit a carbine length system or replace it with a carbine length tube.

Dissapator build? Add a bolt on gas block, either A2 or railed. If you need to add, some cut up beer can shims under the block so it doesnt slip. Or...add a chunk of picatinny rail to the existing handguard and adjust the elevation on your front sight. No need to buy a new handguard if you're happy with the existing set up and just want a front sight.  

Dissapator thread http://www.ar15.com/forums/t_3_118/509821_Dissipator_Picture___Discussion_Thread.html