Gas block/quad rail/ questions

[htttrh]

Hello everybody and Stickman you have already answered so many questions I have had here but I am struggling finding precise answers to my gas block questions. I am curious, I have a Smith and Wesson M&P15OR (Optics Ready) 16" barrel. Ive been adding to it and have decided I want a true free float rail.

I want a 9" instead of a 7"(I have a MI 7" drop in currently) which leads me to believe I will need a low profile gas block for the rail to sit over and want to get a Vltor GB-2SS set screw model to go under a 9" rail, either a DD/MI/Larue and still taking suggestions. Ok with that info heres the questions:

(GAS BLOCK)1. The current gas block is a flat top railed one, it is held in place with one taper pin, now with the Vltor does it come with a gas tube? Is this gas tube the proper length? How much tolerance do I have when placing the new gas block gas port over the barrel gas port and is there a no-miss way to do that? How much torque do I apply to the set screws? Do i have to dimple the barrel? Are these aftermarket gas blocks good and deliver great service?-----Im really concerned with proper placement of the gas block and gas tube length if you could hit on those points it will be greatly appreciated.


(FF RAIL)2. Im concerned with a rail that could possibly twist and damage the gas tube so I was curious what holds the MI mctar-20 in place. I know the Larue is suppose to never move and have seen the install on that and it looks completely reliable but I like the DD because it gives you no interruption in the flat top rail and it too looks like it has a system to allow it zero movement.


The gas block getting properly installed is a primary concern but am also lookin for some pros and cons on the above mentioned rails so THANKS! IN ADVANCE!!!

[Stickman]

I'll go over this in more detail when I get back, but for now, I need to know if you are installing this yourself, or if you are having someone else do it. You've got a few different options with this one.



My first inclination would be to take a dremel or cutting tool to the existing gasblock, and make it a lowprofile version myself.

[htttrh]

Thanks Stickman, I am doing this myself, Im capable of doing most things Im just very particular and want to do things right so I try to get any and all info before I start a job like this. THANKS SO MUCH, I will await your reply!

Oh, I just saw your post about cutting the block, I did look at that option and it looks like I would not be able to cut it to fit, just because of the way it is made, I will double check.

I really appreciate your time and will post pics and stuff

[Army Chief]

I'm capable of doing most things I'm just very particular and want to do things right so I try to get any and all info before I start a job like this.

I very much like the way you put this. I'm capable of doing most anything, but necessarily to my own high standards. LOL I usually defer to a professional, not out of necessity, but merely out of preference. If we still have these same opportunities when I'm able to retire in a few years, I'll no doubt take a lot more active role in advancing my assembly/modification skills, though I suspect what we're seeing now on the political front is merely the calm before the storm. That's a sidebar discussion, but in any event, I applaud your approach.

AC

[htttrh]

I very much like the way you put this. I'm capable of doing most anything, but necessarily to my own high standards. LOL I usually defer to a professional, not out of necessity, but merely out of preference. If we still have these same opportunities when I'm able to retire in a few years, I'll no doubt take a lot more active role in advancing my assembly/modification skills, though I suspect what we're seeing now on the political front is merely the calm before the storm. That's a sidebar discussion, but in any event, I applaud your approach.

AC

I hear you, I too will pass work onto a professional, but if I can do it Id really like too. I just really want to know more.

I sure have kicked the crap out of myself though on jobs Ive started and screwed up, that was the more impatient Steve, these days I throttle back and look into the pool before I jump in. Nice chattn with ya!

[Stickman]

Are you comfortable pulling the barrel nut off, or is that something you are trying to avoid?

[htttrh]

Im very comfortable with that, I can break it down, I just dont have a whole lot of specifics on gas block placement, after market gas blocks, proper placement, gas tube lengths and so on, Thanks!

[Stickman]

Im very comfortable with that, I can break it down, I just dont have a whole lot of specifics on gas block placement, after market gas blocks, proper placement, gas tube lengths and so on, Thanks!

Stay with quality components, and you shouldn't have any problems. My own weapons tends to use Vltor or DD low profile gas blocks, with DD Lite rails.

The gas tube that is on the weapons now, is the same one you want to stick with. There is no reason to change it out.

If your gas block is a pinned version, I would try cutting it down and using it. Since its simple to spray the cut area with high heat ceramic header paint, and its going under a rail, that pinned block would be a great way to go. If you want to avoid doing that, mark the center of your block in front and behind it on the barrel, so that when you replace the block, you have an easy reference point.

The gas block is really not a big deal. Once its on, flip the weapon over, drop the BCG inside, and run it back and forth to ensure that everything is smooth and lined up correctly. That is whats important, and its pretty easy once you have done it.


Another option is to go with a longer rail. Its not needed, but as long as you are swapping the parts out, its something to consider.

[htttrh]

Thanks so much for the help, just one more:

if I cant use the gas block I have now is the Vltor a quality product?

The DD low profile gas block is a 2 clamp model how does it rate in your opinion?

Are PRI gas blocks high quality?

and would you recommend clamp or set screw?

and if you suggest set screw do I have to dimple or tap the barrel for set screws?

and if I have to dimple the barrel whats the best way to dimple in your opinion?

Sorry for the hassle I just dont want a micky-moused AR....Thanks STICK!

[Cannon549]

I'm in need of a quality 2 piece gas-block. I currently have a yhm 2 piece gas block, with flip up front sight (all-in-one deal) and don't like it. Unfortunately I have a 14.5 inch barrel that has the flash suppressor pinned and welded. At this time I don't feel like buying a whole new barrel and suppressor. I would like something low profile and have only been able to find big bulky ones that are going to give me an extra foot or rails.

All I need is something simple, but I've looked just about everywhere that I can think of.

I know that it's the cheap way to do it, and I should just break down and get an SBR, with a quality barrel but I don't feel like going through all of that again.

Any advice?