One of my AR's has a Lightweight barrel (.625") with a Low Profile gas block and a Carbine length gas tube. It used to have a free float handguard, but that was transitioned to my 10.5 SBR.

I would like to build a Faux Dissipator with the gas block hidden under a Magpul MOE Rifle Length Handguard. The problem is that I'm having a hard time trying to find a standard A2 style fixed front sight base with an inside diameter of .625" that does Not require drilling/pinning it to the barrel. All the clamp-on models I've seen are either for thicker .750" barrels or flip-up.

I have nothing against flip-up sights as my 3 other AR's have them and work just fine. I just want to build a fixed sight rifle, with a long sight radius in a 16" package; a K.I.S.S. Dissipator Carbine, if you will.

And so the question is: Does anyone know of a standard A2 style fixed front sight base with an inside diameter of .625" that does Not require drilling/pinning it to the barrel?

A second question: My Low Profile gas block is a YHM Spector. Does anyone know if this will fit under the Magpul MOE Rifle Length Handguard? Or will I need something smaller?

CLICK HERE for a quick representation of what I'm trying to accomplish. Thanks to Gunstruction and everyone involved.

Long time no see... will help and see what I can find

Here.  They have a few varieties

This one does not require pins, as you requested.    

rguns

Thanks for the response guys!

rauchman: You're right. They have several varieties, and one in particular that the "Front Sight Base is drilled and tapped for SET SCREWS for barrels with or without taper pin holes/flats. Set screws are positioned low to “WEDGE” against the barrel for a very solid fit." Good stuff for a decent price. Can't tell if it comes with the front sight post, spring, & detent, etc. But I will find out. They even have a version without a bayonet lug, which might be a good idea considering this is for a Dissipator and there's no room for a bayonet anyway.

STL_Nik: I think your's has the same set screw design as rauchman's, for less than half the price. PLUS it looks like it comes will all the trimmings (i.e. front sight post, spring, detent, and sling swivel). It mentions a 5th set screw, gotta find out whats that for. Only the .750 version comes w/o the bayo lug, but no biggy.

I will be contacting both vendors to get more information on what each one comes with and exactly how they mount to the barrel. Thanks for the awesome finds. As always, ARFCOM to the Rescue!

UPDATE:
I contacted RGUNS and they say the 5th set screw goes under the sling swivel.

Also found another retailer: DEZ ARMS, INC.
They have the same thing, but the FSB alone goes for $33. They sell the sight post/detent/spring and sling swivel/rivet as add-on's for $5 each. So $43 for everything, plus $10 S&H brings the grand total to $53.

Looks like RGUNS is winning @ $25 for the whole shabang. $15 for S&H totals $40. More to come...

The wedge ones from Fulton Armory work very well.  They do not come with the front sight post/detent/spring.  Quality parts though.

I have a DEZ arms one if you have any questions.

Hi there shadohh,

I guess the most important question is How well does it hold up? Does it stay in place?

Some say the 4 side set screws would continue to slide around the round barrel no mater how tight, causing it to cant. I've heard of people dimpleing the barrel so the set screws would hold better.

Your thoughts.

I put the DEZ FSB on a faxon 20 inch gunner barrel.  The fit was tight enough I had to heat up the fsb and make the barrel cold.  This makes the FSB unmovable by hand without any set screws. I am pretty confident it will hold given the tight fit.

If you are worried about it moving around you could always dimple the barrel.

I hope I don't have to heat up mine when it gets in. But we'll just have to wait and see.

I was a little hesitant to dimpling it myself, but after watching a few YouTube videos, I'm pretty sure I can handle it. At least the one in the bottom hidden by the sling swivel.  I dimple that one good and the other 4 shouldn't be a problem.

Thanks again for the advice . Do you mind posting a pic of your setup?

Its not entirely done, need a charging handle.

I have an older colt one if you need one

I have one of the set screw Dez models, it moves under recoil, recommend against a set screw version.

The AR15.com store sells a low profile .625 has block for a reasonable price..625 Gas Block

Shadohh, nice set up.  I might do an all wood setup later down the line. Maybe if ever pick up an original Colt SP1.

Garr, thanks for the link. Once the MOE hand guard come in, I'll confirm the fit of the spector gas block. If no go, I'll definitely order a set.

Myhatinthering, what "older colt one" are you referring to? A FSB? Please send pick.

I would also like to say DEZ arms is top notch. I lost one of the set screws and I emailed them asking them for the spec on the set screw so I can purchase replacements and they are sending me replacements free of charge.

Just a quick update: I tried to fit the YHM Spector Gas Block inside of a mid-length MOE handguard and it was a No-Go. The gas block is too big to fit inside the heat shield. Looks like I'll be ordering a standard lo-pro gas block.

Luckily for me RGUNS has a set for only  $30.

More to come as I collect all the pieces.

Alright. Finally ordered and received all the necessary parts. Was finally able to to assemble my New-ish Dissipator Carbine.

Please CLICK HERE to see how it came out. (Sorry for the Link but Photobucket was not responding )

Pretty sexy bro!  I am working on a dissy myself.

If you plan to keep it iron might I suggest a sight?

http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=320&CFID=596209984&CFTOKEN=36501410

I have those. They're great