AR 15 front sight options

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rifleman14

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Hey everyone, Im looking to replace the fixed standard A2 front sight on my AR15 with some kind of flip sight. I was looking at the YHM front sight/gas block that bolts on but i heard that the screws can come loose and that the bolt on gas blocks arent as sturdy as pinned on ones. Anyone have the YHM front sight gas block that would share their opinion? I dont have a free float railed handguard, just the standard M4 style heat shield handguards. With that in mind, what are all of my options for replacing the front sight? Good solid gas blocks, folding front sights, etc.
Thanks for the info everyone,

Dylan
 
The going trend is to use a lowprofile gas block that a railed FF forearm can go over. Then use long rifle length forearms that'll allow you to have more room forward on the grip to stretch out.

Then just pop a set of Troy or Diamondhead sights on your top rails.

if your going to stick with standard m4 grips, then i would stick with the standard Ar front sight/gas block as well.
 
i am keeping the M4 handguards but not the standard front sight/gas block. it gets in the way of my red dots sight picture and i like having a clear sight picture
 
come on guys i really need some help on this so that i know what my best options are and so i can plan how my money is spent.
 
zerodefect, the second link you posted is the same front sight that i was talking about and considering, the YHM one...the only thing i was worried about is that its a two piece "bolt on" style rather than a pin style like the standard A2 sight. that was the main reason for my starting this thread; i had heard that the bolt on style like that YHM sight wasnt as sturdy as the pin style and could move during firing. is this true or are the bolt on style gas blocks equally sturdy as the pin on style?

The problem is that i am on a very tight budget. I am using a cheap NcStar red dot on a YHM 1/2" riser. the iron sights take up half of the sight picture but i like the height of the optic which is why i need a folding front sight.

Here is what i have come up with from my research as possibilities for gas blocks but i NEED clarification on how sturdy they will be and if the bolt on style is as sturdy as the pin on standard A2 style front sight.

http://www.pistolandpawn.com/store/...=27016&zenid=a8aec6e7ca0781e3e04d7c873e072bfc

that first link is to a doublestar one that uses what i understood to be "standard height" for railed gas block rails. (1913)? This one is secured by 3 set screws on the bottom though which i dont fully understand and would like to know if they are sturdy and will move when firing.

http://www.midwayusa.com/viewproduc...urce=froogle&utm_medium=free&utm_campaign=649

the second link is for the same YHM sight but with the hooded sight rather than the standard style where the two walls on each side of the post point away from the the post. i prefer the round hooded sight which is why i posted this link. Again, my worries are that since its bolt on, it may not be as sturdy but again, thats just something ive heard through research and dont know if its true or not.

http://www.midwayusa.com/viewproduc...urce=froogle&utm_medium=free&utm_campaign=649

The third link is absolutely last resort because of the fact that im on a budget and would also need to purchase the flip up front sight which will make it the most expensive of my three options. this one is a cross bolt style which seems to me like a happy medium between "pin on" and "bolt on". it seems to be a great gas block but i would like to hear everyones opinions on the other two links first because as i said, this is a last resort and is more than i would like to spend.

thanks for any future help, its greatly appreciated

Dylan
 
As Zerodefect said, if you're keeping your M4 handguards I would keep the A2 front sight. Surely you can find a slightly higher mount that will give you the proper 1/3 cowitness and avoid replacing your pinned FSB. It's a good thing seeing/cowitnessing your front sight through the red dot - not bad. And this is the low cost solution as well plus you wont find a flip up as tough as what you already have.
 
please respect my desires. i do not like cowitnessing iron sights as i find the front sight distracting in the sight picture, even if the red dot is not on the sight, the front sight is still in the sight picture and i find this distracting. this is simply personal preference and i would like my rifle to fit my personal needs and likes. i can still cowitness a folding front sight through my red dot by simply flipping it up if i need to. my red dot is my primary aiming device on my rifle, not the iron sights(hence the term, back up iron sights). therefor, i would like for the red dot to be the ONLY thing i am aiming with, without having the front sight get in the way.

I am not trying to offend you or say that you or anyone with opinions similar to yours are wrong, im simply saying just that; they are opinions and i have my own and would like to fulfill them by making my rifle comfortable to ME.

Thank you,

Dylan
 
I have the YHM folding BUIS/gas block.
Here is what I did, but I am guilty of over doing stuff.

The screws feed in from the six o' clock position IIRC. Blue locktite is your friend. Apply liberally. It drys slow, so you can wipe excess off upon completion. Doing a bolting patern ie dont tighten one side. Go in a star pattern. Think 25% of torque increments side to side.

When you have achieved the desired torque you will have 1 or 2 threads sticking up in the 12 o' clock position. I then staked with a semi pointed punch, top (threads) and bottom (heads).

I'm at 1000 rounds at this set up with zero issues to date.

I am not a professional and do not compete (yet) just a bubba who has built aprox 50 rifles for myself, friends or family.(them buying their own lower) I have yet to have one come back with issues.

Just my $.02. If this does not work for you, I will refund your $$$$ in full
:)
 
Well definitely do what what you want, it is your rifle. Sounds like you basically want to retrofit your barrel something like the S&W M&P15OR or other optics ready uppers which makes for an extremely flexible rifle. My ArmaLite upper is that way with a railed gas block. I have a fixed sight bolted on but of course a gas block flip up would work well.

In regard to your question on the YHM two piece block, my gas block is clamped on with set screws. I don't see any evidence of it moving after many, many rounds have been fired but I did make witness marks and check them often just in case. I really don't think it will move unless it got rapped hard and repeatedly but no doubt that a pinned gas block is more desireable. Good luck in your search.
 
mot45acp, thats the kind of post im looking for. i just need reassurance that the product i will be purchasing will be worth the money. i can definitly loc tite it but might not stake it at first simply because it may be slightly overkill and an unnecessary risk that i could mess up lol.

when you installed the sight, did you have to "center" it so it wasnt tilted? i can never get scope crosshairs level even with the "level level level" tool so leveling the sight may cause me quite a bit of frustration...



Quentin, would you possibly be able to describe in detail how the set screws secure the gas block to the barrel? do they just tighten onto the surface of the barrel? to me, it doesnt seem like that would be a sturdy securing method


Thanks for the info everyone, keep it comin

Dylan
 
Quentin, would you possibly be able to describe in detail how the set screws secure the gas block to the barrel? do they just tighten onto the surface of the barrel? to me, it doesnt seem like that would be a sturdy securing method
Click to expand...

The ArmaLite gas block is a big chunk of metal about 1.5" long that fits snugly over the barrel then is clamped with two set screws (which do not contact the barrel). No doubt pins would be better but this clamping method seems to work as ArmaLite has used it since 1999. It is definitely on TIGHT! If you're interested here's a link to what it looks like and the price. Fits a standard 0.750" barrel. Any flip up sight designed for a gas block rail should work on the ArmaLite block. I chose the fixed sight that also can be seen in the link. I notice that it looks somewhat like the 3rd YHM gas block you linked but has much more metal contacting the barrel.

ETA: This kit seems to be missing the sling swivel that mine has. It also does not have a bayonet lug (mine doesn't either). And of course will require a gas block sight. So it does look like your second link may be the simplest and most complete solution especially since Mot45acp has had a positive experience.

http://dsgarms.com/index.cfm?fuseaction=product.display&Product_ID=756
 
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I've been using the YHM sight like you describe on a "pencil" bbl. for over a year now without it moving. I also replaced the standard handguards with a YHM one piece lite forarm that "floats" the bbl. Loctite and torque are your friends.
 
thanks for all the great info guys. looks like im gonna give the YHM front sight/gas block a shot once i get the money saved up.

ive also got another question that somewhat relates to the topic of this thread so i figured i'll ask it rather than starting a new thread...ive had trouble with optics on this AR, trying to figure out which optic/riser rail(if needed) will give me the perfect height for comfort when i look through the optic. right now my AR is sporting the cheapest and lowest quality red dot money can buy(NcStar red dot "tube") on top of a YHM 1/2" riser. This setup is tall enough for me to see through but its not that "perfect" height. Id like it to be just a few milimeters higher. I know i know, eotech or acog are the way to go but im relatively cheap and just cant see the logic in spending $400+ on a red dot sight. so after weeks of research i finally stumbled across the bushnell trophy red dot sight, the one in this link; http://www.opticsale.com/bushnell-t...k=gdfV2656_a_7c772_a_7c3291_a_7c027_d_730132P
I was wondering if anyone has experience with this red dot sight and could tell me how they like it. hows the height on it for an AR15? will i need to mount it on my riser rail or can i mount it right on the flat top rail of the rifle? this seems like the best option ive found both for cost and because it seems to be the perfect optic for my needs. So let me know what yall think of this red dot!
Thanks in advance,

Dylan
 
I actually prefere the clamp on types of gas block over the pin on and set screw.

The pin on types have not a lot to keep them from being knocked crooked. If they werent so darn tight we'd see more of that. But for what they are they work well.

The set screw type need a jig block bolted on so you can drill dimples into your barrel that will locate the gas block. I use these for low pro gas bocks only, not sighted blocks because its easy to drill wrong and screw it up.

The clamp on types can be very tough. I put them on with CLP oil and shot my gun to make sure it works. Then I mark the gas block and barrel with a sharpie, punch, or awl scratch. Then I remove the block if needed or just loosen it and coat the inside edge of the block with red Permatex thread lock. And use red permatex on the bolt threads. Plus since they clamp on, as long as thier tight they aren't going anywhere.




Anything that can knock a properly installed clamp on crooked, probally would have damaged the sight anyway.

The red threadlock is really good at glueing metal parts together and keeping them from vibrating apart. Red Surelock is better at filling gaps between metal than red Permatex threadlock.

I think Knights Armament, KAC makes a gas block/ flip front site combo your looking for. The Magpul guys used it (I think) in there Art of the Tactical Carbine 1 DVD. They used rails behind it, but i think it was still the type that accepts M4 hand gards. I see If I can find a linky.


KAC has some bada$$ stuff:
aaaakacgasblock.jpg

Unfortuneatly this model is not on KACs website yet. And given that the AR evolution has gone allmost totally to rifle length handgards on carbines, I'm not sure it would be wise to produce. Most KISS and lite builds use a standard front sight.
 
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so what youre saying is that you actually prefer the bolt on style over the pin style? great to hear, seeing as how im going with the YHM gas block/front sight :)

when you install a bolt on style gas block/front sight, do you have to center it? is there a chance of putting it on slightly crooked?

thanks,

Dylan
 
the screw on type sights are fine. As with any metal parts. It requires more than finger tight.. I've put on MagPul Buis, Troy's, YHM, ARMS, GG&G and a few dozen others on rail systems. M-4's have used them for years.. A little reasonable force on tighting them and they stay where you put them.
 
come on guys i really need some help figuring out which optic i should purchase. im going to list a few that look decent to me. if yall could tell me what you think of them, especially those with experience, id really appreciate it. also, im havin a lot of trouble figuring out if i will need my riser for any of these sights to get it to the right height to where my eye lines up with it...if anyone could help me out on that problem i would be very happy!

1. Bushnell trophy MP red dot http://www.midwayusa.com/viewproduct...tnumber=859535

2. Walther PS 22 red dot http://www.midwayusa.com/viewProduct...tNumber=655370

3. Walther PS 55 (does anyone know what reticle this sight uses?) http://www.midwayusa.com/viewProduct...tNumber=987515

4. Aimshot holographic http://www.midwayusa.com/viewproduct...tnumber=314177

These are just the ones that i was able to find in the midwayusa master catalog that looked decent. If anyone has any suggestions for sights that i havent listed, please feel free to post them. I am looking for something with no zoom. I would prefer a reflex style sight like the last link because of the large field of view but i will consider other styles, such as the first three i have listed I would really like to spend $150 or less because if i have to spend more to get a big name sight, itll be a very long time until i can save up that much money. Do i really need to go with an eotech or aimpoint or will one of these sights or another one that i dont know of be good enough for a civilian shooter who would like to have a durable sight just in case the russians come rolling down my driveway one day?

Again, my main concern is finding a setup that will give the proper sight heigth to line up with my eye as comfortably as possible, so please help me out on this.

Thank you all very much for any help that you can provide me with!

Dylan
 
DBR I was actually about to recommend the Vortex dot!

I have owned 2 of them and ill tell you what, it holds SOLID and dead on Accuracy for the $$! I am using one on my AR and so far, its pretty awesome! VORTEX also has a spectacular return for repair/replacement policy! I had a little problem with one of my lens caps it came with, they said to send it back and gave me a whole new SCOPE!! I am very pleased with mine!

AND to add on to the whole sight and co-witness talk, I am currently running a DPMS railed front gas block with a standard Flip up front sight from UTG, and that Red dot sits dead center on top of the sight post when the front sight it UP. And when it is in the down position, there is a nice CLEAR unobstructed view!

Also Rifleman, i noticed the 3rd YHM gas block you have listed, the Railed one w/o the front sight... I have one in the Mail coming to me as we speak from MidWay. I will update you on how it works out when i get it installed Hopefully this weekend! :)

--Chris
 
I'm hard on gear. Most lower end scopes don't last morethan a few days on my rifle. Then again, when dropping to urban prone, i have a nasty habit of wacking the ground with my rifle.

My recommendation:
http://stores.homestead.com/Laruetactical/Detail.bok?no=20


Larues mount holds the sight at just the perfect height for comfort, speed, and, lower 1/3rd cowitness. The cantilever mount puts the scope further foward, which speeds up how quickly you can pick up the red dot/blob.
 
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