After looking through a couple of the picture threads on here. I've noticed that 90-95% of the knowledgable/experienced AR owners use the stock front sight post (non-fold down) with the fold down rear buis. Why isn't there more users using the fold down method for both the front and back sights? Just seems to be more uniformed this way. What am I missing? I'm trying to decide on a set of iron sights and I'm pretty solid on getting the KAC #40 BUIS, I'm just un-decided on the front sight for my front Pic gas block. TIA

You mean an ARMS #40.  

Bushmaster has a decent flip-up front sight for the picatinny gasblock.  

Most of the time the standard A2 tower will not interfere will the sight picture of you optic, unless it happens to be a higher magnified scope, then again it rarely causes an issue.

Using the A2 tower gives the operator one less thing to worry about if and when his primary sighting system fails. Flip this, flip that.

A fixed front sight is free and can be worked around to use any optic.  The rear sight gets in the way of a scope and can be annoying with some dot sights.

A folding front sight worth owning like the PRI unit is almost $200 and requires removal of the front sight and any muzzle device as well as removal and reinstallation of the gas tube.

The new SPR rifle used by special forces uses the PRI front sight or the KAC folding front sight.  The KAC unit is much easier to install as it sits on the front of your FF rail system but is not nearly as robust and knock down proof as a PRI unit.

Most people will not blow $200 on something they normally get for free.  Its like buying a gull wing door coversion for a custom car... few people do it even though it reduces the odds of your hitting objects with your doors and looks cool the stock doors work just fine.

I've never handled the PRI flip up's but all the ones I've inspected thus far seem cheap and flimsy.  Even the Bushmaster didn't feel solid when deployed.  It had some play to it.

I went with the detachable front sight and a #40. The front sight feels and sights just like a standard one, but its easly removable, so the option is always there if I want to pull it off.
[img]http://www.cmmginc.com/cmmg_images/tbl_images/accessories_images/Front_Sight_Weaver_Base_Combo.jpg[/img]

The PRI is very well designed.  However, it's installation frequently involves some minor gunsmithing.  The KAC flip up front is too fragile for military use.  Unless you will be using magnified optics, the best value is the A2 tower.

The stock front sight dissapears through optics. In my experience the fold down front sight is an answer to a non-existant problem. Plus it replaces a rock solid front sight with a (sometimes) spring loaded "shear pin" solution.

Bob

I'm thinking about getting an eotech....would that be an issue if you have a swan-sleeve?

I went with the Bushmaster BMAS flip up front on my RRA Mid-length weaver front gas block.

My reasons were pretty much as stated by others. My intent was to build a truly modular weapon that could rapidly be changed from a scoped rifle, to a CQB rifle utilizing no magnification optics such as the EOtech.

The BMAS flip up is simple and robust. It is my humble thought on the matter that a blow to the front sight and gas block, hard enough to destroy your deployed BMAS front flip would in most cases be a blow hard enough to F**k up your fixed front sight as well. It's usualy a good idea not to use your weapon as a crow bar, or door breaching tool.

I saw a funny thread on here the other night entitled "why did Gene Stoner design a rifle with a carrying handle?". I think an even better question would be "Why did Gene Stoner design a rifle with a Bayonet Lug?

The M-16 and AR family of weapons were never intended to take the kind of stress metered out by pounding on things or using your weapon as a pole arm with something pointy on the end.

If your on this web sight, chances are that you want to know more about the high tech black rifle you own. So let me impart this one small bit of truth to you. THE PRICE OF CARRYING ONE OF THE MOST HIGH TEC RIFLES EVER DEVISED...IS THAT YOU HAVE TO TAKE CARE OF IT.

That means, being able to be tactical and chew gum at the same time and avoid banging your weapon on S**t

It also means that people who tell you you need a bayonet or a bayonet lug, should be treated with scorn. A bayonet is about the least useful item you will ever buy for your AR.

Take good care of your AR and it will take good care of you.

Just remember, there are guys on this sight that could break an anvil and then blame it on the fact that the anvil was not Mil Spec.

HAY!!!

I take issue with that statement.
The anvil I broke was a DEFECTIVE Mil Spec anvil [B)]

Sometimes, no matter how careful you are, sh*t just happens (especially when people are launching lead objects your direction). My concept is to keep a combat weapon as functional, light, and robust as possible. The factory front sight tower fits the bill, so why mess with it.

Many don't build up their AR's to be combat -in da mud- type weapons, as they are sporting arms, precision rifles etc. Which is cool too. [8D]

Aristotle13, get the GG&G flip front BUIS for the gas block with rail.

Except for one upper I have, all my flat tops eventually get a flip front BUIS.  Necessary? No, but it just annoys me to see a shadow in my optics due to a sight tower.  However, as pointed out, it takes skill or money for someone to install a front flip.  I got the PRI, but I actually like the GG&G better cause I just like the looks and it has a bayonet lug to tweek the PC people.  Would I use a bayonet on it?  Of course not, though I might use an attachment that utilizes the bayonet lug (light/bipod/laser).

My Armalite came with a gas block with rail, and I got the detachable tower, but I like being able to instantly flip the sight up or down and not have to worry about loosing it cause it's been removed from my rifle.  I used the GG&G flip for gas block rail and am very happy with it.

With a SHTF rifle, I prefer the standard sight tower. YYMV.

Optics are here to stay... The fixed front sight is an anachronism...The PRI is a great unit...

Well, i'm sorry to say that i'm not able to offer any personal experience, but what i CAN say is that after much deliberation i decided to get the bushmaster BMAS front sight for my dovetailed armalite gas block.  I am also planning on getting an EOTech in the near future, so i wanted a BUIS system that would sit completely out of my way until i wanted/needed it.  

but alas, i won't be able to piece my AR back together until i come back from college for thanksgiving   :(

I have to agree with the fixed front sight for carbines.  I have no desire to replace a functional fixed sight with something else.

But for a rifle which has a railed gas block, I'd rather have a flip-up front than a detachable one.  

I'm in the same dilemna; fixed or folding?

For those of you who own a rifle with a fixed front site and use an ACOG w/TA-51 base mounted on the flat top; do you have any optical problems, distortions, shadows?  Does it interfere with the combined operation of the ACOG and shooting characteristics?

Cheers!

Good choice.  Same thing I've got.  You won't be disappointed.