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specops2k3
01-17-07, 10:37
:confused: i own a bushmaster AR and want to convert my front sight tower to a low profile gas block so i can extend my rail over it and use flip up front sights. how hard is it to install a low profile gas block and does it require a weaponsmith to do it?

Harv
01-17-07, 22:19
Here's a pic of my home made lo-pro gas block. I made it from the FSB of a Bushmaster that I wanted to install a 12" Samson FF rail. So I spend a few evenings in the basement with a dremel and about 7-8 sanding disks and some patience and Viola. To insure the gas port aligned perfectly I made a spacer from the front hand guard cap so as not to change the profile. After some final sanding to get the right contour and a few coats of paint...viola... http://img.photobucket.com/albums/v494/harv24/IMG_1344.jpg

Dave L.
01-17-07, 22:21
Now why didn't I think of that- Harv you might be on to something here:D

Robb Jensen
01-18-07, 07:23
Harv,
you don't have to use the handguard cap (a spacer now) to line up your gas block. Your taper pins will align the gas block automatically. Using yours isn't going to hurt anything, it's just not needed.

I use a modified handguard cap as a spacer when installing gas blocks that use set screws though, I use them to just get the gas block the correct distance from the barrel shoulder to correctly align the gas ports in the gas block with the barrel, then dimple the barrel for the set screws and assemble with Rocksett.

rob_s
01-18-07, 08:50
Awesome job Harv. I punked out and paid ADCO to do it for me, as well as install the DD rail I bought from them.:p

specops2k3, what brand/model rail are you planning on using? If you go with Larue, the best thing to do, and damn near the only thing, is use their own low profile gas block. If you go with Daniel Defense, you can just cut down the stock FSB.

I prefer the cut down FSB as it re-uses the taper pins (in the case of Colt) and stock alignment. While I do believe it is possible to get the low profile gas blocks as secure, it takes alot more work than most people realize. it's not just a matter of sliding it on and tightening the screws.

Harv
01-18-07, 20:06
Duh.. I never thouht about the pins aligning the gas port...

My main goal was to have a lo pro that was pinned vs. set screw (I know... I'm anal) and it fit under the FF rail I put on it.

My first major dremel coble job and I do say, I rather proud of it.:cool:

Rob.. I would have done he same thing if I would hae gotten the LaRue and sent it out.. I know when I get in over my head on certain jobs... But I got sucha ood deal on a Samson 12 FF rail, that it was easy for me to install. Just needed the Lo-Pro Gas block and I was all set.

VA_Dinger
01-19-07, 23:09
Wow, great job Harv.

You got a pinned low profile gas block for a damn good price. All it took was some time & effort.

It looks great.

BushmasterFanBoy
01-20-07, 06:37
I had AR15 barrels do mine for me when I put on my LaRue 13.2. I thought about the dremel but decided not to cheap out on it. I don't doubt for a second that it would work, there's no reason why it wouldn't, is there?:confused:

I love my rail, even if some say it is uncalled for or too big or too heavy. It keeps my hands cool, even after tons of fire, not to mention it makes a great mount for my Eotech, so I can get great eye relief and puts my optic right above my VFG. Plus the extended sight radius is great too!:D

Harv
01-20-07, 18:26
Here's a few more pics of the install and final product...

http://img.photobucket.com/albums/v494/harv24/IMG_1348.jpg

http://img.photobucket.com/albums/v494/harv24/IMG_1349.jpg

http://img.photobucket.com/albums/v494/harv24/IMG_1346.jpg

Robb Jensen
01-21-07, 05:30
Looks good. You aren't supposed to use any washer (peel or crush) when using a Vortex flash suppressor, When I install them I only put them on a few lbs past hand tight (no more than about 10ft lbs).

Submariner
01-21-07, 06:20
No more RAS, Harv?????

Harv
01-21-07, 11:28
Don't worry Paul... My RAS ain't going anywhere....;)

This is my Second AR that is my new project gun...A more precision rig that I am slowly piecing together.

As to the crushwasher.... As I understand it.. a crushwasher is not "required.

And I'm an "Overkill" kinda guy anyhow......;) My experience has shown me that nothing.."Self Tightens".....;)

Submariner
01-21-07, 12:22
Don't worry Paul... My RAS ain't going anywhere....;)

Aw, shucks, I though you might be needin' to sell it real cheap.:D

To help fund your precision carbine of coors.

Hoplophile
01-21-07, 15:41
As to the crushwasher.... As I understand it.. a crushwasher is not "required.
The instructions that came with the Vortex explicitly state that you should not use any washers because it alters the internal dimesions and reduces the effectiveness of the device.


My experience has shown me that nothing.."Self Tightens".....;)How much of that experience involves the vortex? It self tightens for the rest of us. ;)

Harv
01-21-07, 19:16
The instructions that came with the Vortex explicitly state that you should not use any washers because it alters the internal dimesions and reduces the effectiveness of the device.

I think I can live with a .01% reduction .......;) It's a FH... not a nuclear reactor....;)


So it will self tighten against a Crushwasher... works for me.....:cool:

Robb Jensen
01-22-07, 07:58
I think I can live with a .01% reduction .......;) It's a FH... not a nuclear reactor....;)

So it will self tighten against a Crushwasher... works for me.....:cool:

Using washers can make it crack, I've seen it happen twice (not the tines, the body of the FS'r) once from a torquing it WAY TOO TIGHT and using a crush washer and another from just tighting WAY TOO TIGHT with a wrench. Neither guys were graduates of Hooked on Phonics. ;)

Hand-tight and no more than about 5-10ft lbs WITHOUT washers is the proper way.

I wouldn't 2nd guess Smith Enterprises (the manufacturer).

dialM4murder
08-16-09, 16:40
Hey I always wondered what the crown markings meant on that gas block. My Bushmaster ORC
Model has those same markings. Does BM make those blocks or does some one else?

dialM4murder
08-16-09, 17:29
It looks like BM does pretty much the same thing. They simply cut a standard front site post gas block down, and call it low profile.

http://lh3.ggpht.com/_aHHKanqrkY0/Soh74yvnxeI/AAAAAAAAAMM/W0-T__JsrYU/s800/IMG00172-20090816-1733.jpg

Not bad for a camera phone eh?