The only major downside to the 551 handguards is the lack of mounting options for any fore-end accessories.  I wanted to keep this rifle as simple as possible but one thing I really want on any carbine that has guard duty is a light.  So I started reading.  My only current light was a modified G2 in Samco mount.  I knew I didn't want a G2 hanging on the sides of the rifle and I was not really hot on any rail on the bottom.  I decided to look at some of the compact weapon lights and ran across the Streamlight TLR-1

It's an LED based light with a nice 130 lumen output which beats the G2 my M4 had mounted on the lower rail.  It's also light.  About 4.5 ounces.  It's compact and needs no additional mounting hardware and would hug the rifle close.  After seeing a few mounted on ARs I decided to go for it.








Next came mounting.  How should I do it?  After a bit of reading I discovered the small rail sections being offered by TPS Products.  They say it attaches with no modification to 550 series rifles but I am not sure how that is supposed to occur.  Anyway, the location I wanted would mean some drilling.  I had rubber banded the light on for a few days and I knew about where I wanted it to reside.

I marked the locations to drill and then upon removing the guards I noticed a snag.  There are several ribs molded into the interior of the HG that would make it impossible to simply bolt the rail on.  I was going to have to notch that rib to allow the attachment bar to lay flat inside.  I was getting a little nervous about tearing up my HG but decided to press on.  I drilled my holes and I started the notch with a dremel and then finished with a knife to square it out and shave it down level.

Once that was done I mounted the rail and admired the new coolness it brought.  I however noticed the attachment bar was quite thick.  Thicker than needed really since the screws do not bite in that far.  My first thought was.... "Shit, it's not going to clear the gas tube"!  I proceeded to add the HG back to the rifle and sure enough... it has to snap over the gas tube to be installed.  It did though managed to clear the tube once over it by a hair.  I was not to thrilled with this since it will wear on the outside of the tube when removing and installing the upper HG,  I may look at adding a radius to the edges to make it less abrasive.







I reassembled he rifle and and added on the TLR-1.  This involved installing the 1913 rail stop into the interchangeable well in the body of the light.  It includes other stops for handgun rails and comes with the Glock stop installed.  The light has a 'thumb' screw that loosens and then you just snap the light over the rail in the position you want and tighten the screw.  I can detect the added mass up front.  I figure the rail and light return about 50% of the saved weight of the 551 handguards but I consider a light a necessary item on a self defense rifle.











The location makes it a snap to operate the light with my thumb and the light seems to naturally point where desired.  At any range beyond point-blank the core of the projected light is lined up right with the tube of my Aimpoint.  I'll have to see how this goes with the current arrangement.  If it works out badly I may need some new 551 handguards and some green Duracoat.  My initial impression is that I like it a lot.

If I were to do it over I think I would lower the attachment point a bit more to reduce of eliminate contact with the gas tube while mounted.  It's not touching by much but it is touching.  Also, possibly look at having the attachment bar milled down some.  I have no idea why it needs to be that thick.

Some other minor customizations are the addition of the KNS pin to the front pivot pin and some painting of the lettering using my wife's nail polish.  That actually worked quite well!

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good work, i've been considering something similar on my own 556

surefire made an upper handguard for their flashlights for the 551, but I don't think they make it anymore - plus this is a much cheaper solution

I had just added mine before you posted this.  It just took me a while to get some pics up.  I love the TLR-1, good Illum but smaller and lighter than the usual surefire tube.  It actually works well on the left side because I can hold the VFG and click the light on steady or momentary with my left index finger without moving my hands out of a good shooting position.  

http://i232.photobucket.com/albums/ee14/notso69/IMG_0530.jpg

http://i232.photobucket.com/albums/ee14/notso69/IMG_0531.jpg

http://i232.photobucket.com/albums/ee14/notso69/IMG_0532.jpg

Great job there. I wouldn't mine something like on my 556.