Changing AR-15 gas block

[mugable]

I'm pretty sure with the right tools and time I can safely do this myself although I'm no gunsmith.
However I was wondering about the front sight. I want something lower profile as I want to go with a folding front sight.
Should I get a gas block with a rail on top? Or would mounting a folding front sight at the edge of my quad rail pose a problem?
It's a carbine length quad rail, just under 7 inches I believe. If I were to put a front sight at the very edge it would be about 3 inches from the current sight.
I'm just not sure how shortening the distance between the sights would affect accuracy or any other related issues.

 

[HavokCycle]

a few things come to mind -
its relatively easy to change a gas block provided you have a mechanical nature. you'll likely **** up the gas tube pin so make sure the new block comes with a replacement.

get an armorer's tool. the one with several different tools built it. i have a tapco tool, i like it .

if you plan on mounting a sight to your gas block, make sure its a metal one. the gas block gets VERY hot, so a plastic (magpul) will be crap.

i have an aluminum folding front sight on my gas block, which sits a bit lower than my front rail. it is an import thingey, YKM or something, but it doesn't move and didn't require much adjustment (none,IIRC) to get it back to zero.

there is something to be said for shortening your sight picture, but if you mount a sight on the gas block, the post will pretty much be in the same place as the A2 sight you removed.

 

[timsdl72]

a few things come to mind -

if you plan on mounting a sight to your gas block, make sure its a metal one. the gas block gets VERY hot, so a plastic (magpul) will be crap.

i have an aluminum folding front sight on my gas block, which sits a bit lower than my front rail. it is an import thingey, YKM or something, but it doesn't move and didn't require much adjustment (none,IIRC) to get it back to zero.

I've wondered about this. Never used a poly front sight but can't quite understand how they hold up. Several brand name makers have them so I just figured they must be some fantastic plastic. Either way, not for me. I'm just clumsy enough that should the need ever arise for me to break into my version of an all out sprint through the boonies, I'll fall and that front sight will be the first thing I bang on a rock (right after my head).

 

[threedhuntr]

1 other tidbit to keep in mind ....... front sights for gas block mount and rails mount are 2 different heights.

 

[bowtie]

If your changing out your A2 front post sight just purchase a gas block/folding sight combo. Like I have on mine.



However I have plans on swapping it out for a low pro gas block and buying a 14" rail to go over it then buying a rail mounted front sight. Just personal preference but I dont like the way AR's look with the gas block exposed.

 

[wsenefeld]

For a cleaner look, have you thought about going with a low-pro gas block, sell your current rail and get a 9" or 12" rail and put your front flip up on the rail.

Also, if you have a 7" quad rail, and putting a front sight on that only leaves you 3", why is your rear sight also on your quad rail? It should be just above your charging handle.

 

[mugable]

For a cleaner look, have you thought about going with a low-pro gas block, sell your current rail and get a 9" or 12" rail and put your front flip up on the rail.

Also, if you have a 7" quad rail, and putting a front sight on that only leaves you 3", why is your rear sight also on your quad rail? It should be just above your charging handle.

My rear sight is as directly above the charging handle. I apologize for any confusion on that. I was referring to the change in distance from the rear to the front if I were to mount the front sight on the quad rail.
If it were on the end of the current quad rail the post would sit about 3 inches behind where the post on the A2 is currently situated.
I kind of like your suggestion of a low-pro block and a longer rail. That would be a free float system if I'm not mistaken? I still have a bit to learn.
bowtie's rig looks pretty clean too. I'm not trying to be super lazy just cost affective and able to operate within my abilities as far as banging hammers and turning screws goes.
Here's a pic for relevance. I would be mounting the front sight towards the front of the quad rail if I were to go down that road.

 

[wsenefeld]

Swapping out ANYTHING on an AR is relatively easy. My Fortis REV was as simple to install as screwing down 4 bolts.

 

[mvician]

Curious as to the reason why you want to change it out?

 

[sig1473]

Curious as to the reason why you want to change it out?

My thoughts exactly and you beat me to the punch per usual. There is absolutely nothing wrong with a fixed front sight.

 

[Jeremy1066]

If you're going to switch out the fixed front sight, I would definitely go with a low profile gas block and a free float tube long enough to cover it. Then move your flip up sight as far forward as you can. The longer sight radius should increase accuracy, and that setup just looks bada$$. Be careful, however, when ordering a good front sight (I have Yankee Hill Machine on mine and love them, but there are many out there to choose from) that you order a "receiver height" sight and not a "gas block" height. They are not interchangeable.

 

[mugable]

My thoughts exactly and you beat me to the punch per usual. There is absolutely nothing wrong with a fixed front sight.

The same reason anyone else upgrades their stuff I guess. Just because. But to be more specific I've fired several friends' rifles and I had an easier time with target acquisition through an optic without iron sights in the way.
I don't have an optic as of yet but I intend to get one in the future. It may be something I could get used to over time and I agree, there is nothing wrong at all with a fixed front sight.
I guess I just like the cleaner look as well.

 

[sig1473]

The same reason anyone else upgrades their stuff I guess. Just because. But to be more specific I've fired several friends' rifles and I had an easier time with target acquisition through an optic without iron sights in the way.
I don't have an optic as of yet but I intend to get one in the future. It may be something I could get used to over time and I agree, there is nothing wrong at all with a fixed front sight.
I guess I just like the cleaner look as well.

I would keep the front sight then until you get the desired optic you want. No reason changing out the gas block now if you don't have to. Wait until you get your optic and do it then. I have 7 ARs with 3 having the fixed front sight. I used to think that low profile gas blocks were the way to go, but in the end I have learned that fixed front sight gas blocks are the way. If you are looking for a fold down front sight, then check out the ARMS #41-B. I have one on my Noveske 14.5" Afghan.

 

[mugable]

I would keep the front sight then until you get the desired optic you want. No reason changing out the gas block now if you don't have to. Wait until you get your optic and do it then. I have 7 ARs with 3 having the fixed front sight. I used to think that low profile gas blocks were the way to go, but in the end I have learned that fixed front sight gas blocks are the way. If you are looking for a fold down front sight, then check out the ARMS #41-B. I have one on my Noveske 14.5" Afghan.

I'm not gonna be changing it out any time soon I just like to plan ahead. It may sound a little nerdy but I have a notebook for projects of all sorts I'm working on(music, firearms, crocheting.....) where I jot down ideas.
I like to gather a good amount of info before I set any decisions in stone.
That flip up sight/block you linked in your post looks pretty nice. Looks like something of that nature would be more economic or at least easier to set up altogether.
I appreciate the input!

 

[timsdl72]

I have never tried an AR with optics and a fixed front sight. I like the idea of leaving a strong fixed post in place but it does seem like it would interfere with optic use but like I said, never tried it.