Should a quadrail be installed before pinning the muzzle break?

[deerpark 83]

If I'm having compliance work done on an AR, I suppose that the quad rail would have to be installed before the pinning of the muzzle break, correct?

 

 

[High Exposure 5,669]

Depends on the rail and it's install.

 

Whatcha got?

[Vlad G 345]

If I'm having compliance work done on an AR, I suppose that the quad rail would have to be installed before the pinning of the muzzle break, correct?

 

It depends. I depends on what parts you are planning to use. Some "quad rails" snap on in two parts. Some are free floated and need new barrel nuts. Most barrel nuts slip over most muzzle breaks, the problem is the gas block that doesn't unless you replace the gas block with a two piece one.

 

What parts do you plan to use? That is what answer this question.

[pbkid6974 1]

you should pick your hand guard before you pinned it. options are limited once you can't take the gas block off...

[JT Custom Guns 958]

If I'm having compliance work done on an AR, I suppose that the quad rail would have to be installed before the pinning of the muzzle break, correct?

Well the gas block must be installed before the MB is pinned.

The rail depends upon which rail, and how it is installed?

 

If you using a free float, and it fits over the gas Block, than there should be no issue.

If your using a set up that won't slip over the GB, then there are gonna be issues.

 

As H E asked you - Whatcha got?

[deerpark 83]

Well, I dont have anything yet but I wanted to know in which steps to proceed.

 

Based on my understanding of rails, its better to have a single piece "free-floating" rail?  Which rail would you guys suggest?

 

My rifle is on order but I can delay the compliance work if it makes more sense to have everything done at the same time.

[High Exposure 5,669]

I have had great success with the Daniel Defense Omega rails which are two piece free float rails that do not require removal of the FSB or muzzle device. Troy makes a couple of nice options as well as MI.

 

If you have a low-pro gas block installed before pinning your muzzle you can attach just about any one piece rail/tube with no issues.

[JackDaWack 2,895]

a few things to consider... if the brake is flush with the barrel.. no worries, everything will slip over it....

 

If NOT, then

The barrel nut must be on the barrel and the gas block prior to brake pinning

IF you have a low profile gas block, then NO the rail will slip over it, if not then the rail must be on as well, unless it is a 2 piece style.

 

When i had my BCM barrel pinned, i had to give Nick over at Mastadon my Barrel with the Daniel Defense LIte barrel nut and the Low profile gas block. both were in place when finished... i attached the barrel to the upper and the rail slid right over everything.

 

the question is will the rail clear the gas block?

 

the other question is, make sure you pick the rail you want, because your not getting the barrel nut off, and about 50% of the rails out there use there own barrel nut.

[Vlad G 345]

Yep as the others have alluded to it is all about the barrel nut and the gas block. The barrel nut clears most non-absurd muzzle breaks but it doesn't clear any gas block. That means that if you need a different barrel nut for a handguard then the gas block has to come off. This can happen in 2 ways, either it clears the muzzle device (something like the Nordic tactical comp which is .750, the same as the barrel) or the gas block is a two piece clamp on one. Some people really don't like the clamp on 2 piece gas blocks but I've never had or seen an issue with one.

 

Short version: go with a 2 piece clamp on gas block (something like YHM specter gas block. or the JP two piece adjustable one if you are using a bull barrel) and you don't need to worry about the rest. You can always take it apart after the fact if you need to and install parts in whatever order. Alternatively use the Nordic tactical comp, and then everything can come out the front. 

[checko 180]

I have had great success with the Daniel Defense Omega rails which are two piece free float rails that do not require removal of the FSB or muzzle device. Troy makes a couple of nice options as well as MI.

 

If you have a low-pro gas block installed before pinning your muzzle you can attach just about any one piece rail/tube with no issues.

This. Got one (omega rail) from arfcom and it installed perfectly in place of my drop in moe hg's. Very happy

[vladtepes 1,060]

a few things to consider... if the brake is flush with the barrel.. no worries, everything will slip over it....

 

If NOT, then

The barrel nut must be on the barrel and the gas block prior to brake pinning

IF you have a low profile gas block, then NO the rail will slip over it, if not then the rail must be on as well, unless it is a 2 piece style.

 

When i had my BCM barrel pinned, i had to give Nick over at Mastadon my Barrel with the Daniel Defense LIte barrel nut and the Low profile gas block. both were in place when finished... i attached the barrel to the upper and the rail slid right over everything.

 

the question is will the rail clear the gas block?

 

the other question is, make sure you pick the rail you want, because your not getting the barrel nut off, and about 50% of the rails out there use there own barrel nut.

 

 

the last sentence being the most important... 

 

I just dealt with this.. I looked up and down for a free float I could use with a factory barrel nut since my brake was already pinned... ended up cutting off the brake and putting the new barrel on and repinning... 

[pbkid6974 1]

For using the stock barrel nut the troy rails are hard to beat. But if I had to do it over again I would rather have more options to choose from with propriatary barrel nuts.

[deerpark 83]

The rifle is the Colt 6920, not sure if this changes anything.

 

I'm leaning towards something by Daniel Defense, I like the square look.  Quadrail, 1 piece, 12 inch, free float(?).  

 

I was also thinking about ditching the front sight.

 

I still havent decided on a muzzle break.  This looked cool but I dont know if its Jersey compliant:

 

https://yhm.net/annihilator-muzzle-brake-5-56mm.html

 

This will be my first AR so I'm a bit lost with regards to the part names (even the basic ones): "gas block", "low-pro gas block", "barrel nut" and "FSB".

 

I searched around for a diagram and found the following:

 

http://www.midwayusa.com/general.mvc/index/schematics~ar15

[Vlad G 345]

Ok so here it goes:

 

The AR is a GAS operated piston less semi-auto rifle. The gas is bled from the barrel, routed through a thin metal tube and shot at the bolt carrier assembly.

 

The part where the gas is bled from the barrel is generally refereed to as the gas block. In the BASIC AR-15 configuration the gas block is part of the front sigh, it looks like this:

 

 

 

Note the thin tube connecting the front sight tower/gas block to the receiver.  Note the front sight slips over the barrel on two built in "rings". Under the rear "ring" there is a little hole in the barrel that bleeds gases into the front sight assembly, into that little tube and makes the gun work.

 

 

The barrel NUT is all the way at the back under that truncated cone thing (we call that the delta ring). Handguards, specially free floated ones, hang on to the barrel nut and sometimes they need a different barrel nut then the factory one. However the barrel nut would slip freely OVER the muzzle device in most cases, because it is a fairly large diameter. The problem is that the barrel nut can slip over the front sight and the front sight can not slip over the attached muzzle device.

 

You don't have to a one piece front sight/has block.

 

For one you can have a gas block that is not a front sight, like these:

 

 

Those are just gas blocks, without the sight on them. The primary advantage is that they are low profile so the handguard itself could be much longer and cover the entire gas block, where normally it would have to be short to fit behind the gasblock or front sight.

 

However those don't fix your entire problem because while you might be able to get the handguard itself over them, you can't get the barrel nut over them so if you need to change the barrel nut for a different hanguard you are still screwed.

 

 

Now, back to my original solutions.

 

You have Three choices:

 

1) Build it the way you want it from the start, with the knowledge you won't be able to replace parts without hard work later on.

 

2) Use a really thin muzzle break. The Nordic Tactical Comp (http://nordiccomp.com/retail/shop/ar-15-10/nordic-components-tactical-compensator-223-stainless-steel) is the same thickness as the barrel so any gas block or front sight/gasblock can slip right over it. It is not the best comp, but it is a remarkably good comp and this being NJ we have to make some compromises. It is also only $40.

 

3) Use a two piece gas block. Two piece gas blocks clamp onto the barrel, instead of slipping over the barrel. That means you can always remove them without slipping them over the muzzle break, which means now the barrel nut can slip over the muzzle break.  The disadvantage is that at least in theory they could come loose. In practice, if properly tightened and locktite applied to the screws, I personally haven't see it happen not heard of anyone I know having that issue.  Those types if gas blocks can be low profile or have integrated front sights as well and  look like this (and they come in many flavors, these are just examples):

 

 

 

Hopefully that doesn't make more confusing, and explains some of the terms.

 

[checko 180]

Ok so here it goes:

 

..........

 

 

Hopefully that doesn't make more confusing, and explains some of the terms.

Man I'm glad you replied. I was gonna till I seen this Haha

[High Exposure 5,669]

2 more options to add to Vlad G's post:

 

3) Choose a two-piece free float rail that uses a standard barrel nut and doesn't require the removal of the gas block.

 

4) Use a one piece tube/rail system that uses the standard barrel nut and grind down the front site block to fit under the tube/rail.

[Vlad G 345]

Yeah HE is right, as I was driving to work I was thinking I need to add those as options but I figured he would

[vladtepes 1,060]

4) Use a one piece tube/rail system that uses the standard barrel nut and grind down the front site block to fit under the tube/rail.

 

I just opted to do this because I prefer pinning the gas block VS set screws.. 

[Vlad G 345]

I just opted to do this because I prefer pinning the gas block VS set screws.. 

 

Thread drift warning .. but why?

 

There is not a darn thing wrong with set screws properly installed. People drive cars all day long held together by screws, but somehow a gas block isn't trusted unless it is held in by wedges like an Amish cart. 

 

I know "in theory" screws can move, but so can cross pins. The latter I have seen, the former I have not. I have also seen multiple factory guns with cocked front sight towers that you can't straighten because thats where they drilled the pin holes. I had one of those in fact. 

[vladtepes 1,060]

Thread drift warning .. but why?

 

There is not a darn thing wrong with set screws properly installed. People drive cars all day long held together by screws, but somehow a gas block isn't trusted unless it is held in by wedges like an Amish cart. 

 

I know "in theory" screws can move, but so can cross pins. The latter I have seen, the former I have not. I have also seen multiple factory guns with cocked front sight towers that you can't straighten because thats where they drilled the pin holes. I had one of those in fact. 

 

 

if it was pinned incorrectly from the factory... and not straight or something.. then sure... I would not want that.. obviously.. but the gun came with a working FSB that was pinned... so it was already working...

 

my sample pool is small.. but on my SBR I had the gas block move on me once (set screws)... in fairness since I tightened it back up its been good to go...  once a gas block is pinned on.. I do not see how it could possibly move...the pins are a nightmare to get out... so just by seeing the two different methods and how they attach.. to me the pins just seam less likely to get screwed up once done correctly.. 

[deerpark 83]

Well, I’m leaning towards a 1-piece, 15 inch quad rail.  I think this limits my choices to Troy, Midwest Industries or Daniel Defense.  If you know of any others, please let me know.

 

I think the one in this pic is a 15 inch Troy, which actually looks pretty good.

 

 

I prefer the square look so, for now, its down to the MI or DD, both of which require their own barrel nuts.

 

I am going to contact the gun smith and ask him which he recommends/prefers: grinding down and reusing the stock front A2 sight or replacing it with a low profile gas block.

 

With regards to the muzzle brake, I am considering the following, but I’m not sure if the rail would fit over them:

 

https://troyind.com/muzzle-devices

 

YHM Phantom, assuming its Jersey compliant.

 

http://www.riflegear.com/p-1024-pws-fsc556-compensator.aspx

[High Exposure 5,669]

Well, I’m leaning towards a 1-piece, 15 inch quad rail. I think this limits my choices to Troy, Midwest Industries or Daniel Defense. If you know of any others, please let me know.

 

Check the Troy Bravo for a 1 piece free float full rail, and the Troy MRF and Charlie two piece free float with full rails.

 

Also - Check Apex: http://www.apexhandguard.com

 

They use a clamp on type attachment that uses a standard barrel nut. Note: I have no firsthand experience with this product, but have heard they are good to go.

 

If it was my gun, I would get the DD Omega if I was keeping the FSB or the Troy Bravo if I was gonna grind the FSB.

 

With regards to the muzzle brake, I am considering the following, but I’m not sure if the rail would fit over them

It isn't a matter of the rail fitting over the comp, it's a matter of the gas block and barrel nut fitting over the comp. In and of itself any rail should fit over most brakes/comps - caveat: some larger 3gun type breaks may be problematic.

 

The brake becomes a problem when it is pinned and prevents you from removing the barrel nut or gas black to replace with a proprietary barrel nut or appropriately sized gas blocks for the rail installation.

[Vlad G 345]

Quad rails look cool, but in practice they are a pretty bad idea unless you NEED them. If you need to attach a ton of gear then they make sense, realistically you really don't need that  so now you just have a permanent cheese grater attached to your rifle.

 

Handguards like the Troy one you picture, and a ton of others, that have only the top rail as part of the handguard are the way to go. Nearly all allow modular attachment of rail bits where you need them, so do the new "hot" keymod ones if you want to go that way.

 

A smaller diameter handguard that doesn't try to separate the flesh from the bones beats a big fat quad rail every day in my book.