AR Gas Block Take-Off-- HELP


January 21, 2013, 03:32 AM
Ok, I'm looking to switch out a standard front sight tower with a low profile gas block and plan to trade out the old carbine handguards with a midlength or longer rail.

My question is how do I go about doing this? I don't understand the .750, .625 bore, clamp-mounted or set screw mounted options. Any help is greatly appreciated!

(p.s. I'm sure I'll youtube it as well, but I rather read from the experts here)

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January 21, 2013, 09:05 AM
If its a basic front sight you more than likely have taper pins, these are very easy to remove. They only go in one way which means they come out the same way they went in. If you look at both sides of the pins you will notice one side is smaller than the other, this is the side you want to push.

Once the front sight is removed then you will have to remove the delta ring. This requires a special tool and clamping device. There is a clamshell and a claw style, they both fit in a vise and hold the upper properly so you dont damage anything.

After those two things are removed then you can install the new low profile gas block and then handguard. But you must use a free float handguard if you want to increase the length from carbine to mid. The .750" you were asking about is in reference to the diameter of the barrel over the gas port.

January 21, 2013, 10:08 AM
If you are replacing the front sight gas block you don't have to remove the Delta ring. You have to remove the muzzle device, drive out the pins from the gas block and slide off & on the new gas block.
Are you installing a free float hand guard? If so then you have to replace the barrel nut and delta ring with what is correct for the hand guard you choose.

January 21, 2013, 10:23 AM
Anothrr option is to cut the front sight base down.

Sent from my SGH-T999 using Tapatalk 2

January 21, 2013, 10:37 AM
Correct, the muzzle device must be removed to change out the gas block. Thank you for pointing that out.

But he asked about swapping carbine handguards for a midlength or longer. The only way that I know to do that would be to use a low profile gas block (or cut down current one) and free float handguard of some style.

January 21, 2013, 03:31 PM
Yeah, I gotta get my hand out further on the rail, so a Troy Alpha 15" is in the works. Not too keen to cannibalize the sight tower and I know I'll have to remove the handguard cap and switch out the delta ring for Troy's barrel nut.

My real concern is will I need a specific gas block? I see on Troy's site they have a 2" gas block (.750, which I assume is what a standard M4 profile barrel is?) that pretty much looks like a cut down sight tower, but they also have a few others without that space between the two bands (on sight tower, where the bayonet lug sits and the sling loop sits). Does the space matter?

January 24, 2013, 06:26 PM
Cutting down the front sight post is done a lot. Bushmaster did this for years.

January 25, 2013, 12:21 AM
Oh I know they've done it and it can be done but I'm mainly not cutting it down bc it was a gift and I plan to return the parts I don't use or switch out for use on future rifles. Not to mention other than a hacksaw, I doubt I could do or with my tools. Not much of an armorer.

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