Single rail gas block for AR 15

[Doxiedad]

I'm going to be getting a S&W M&P15A. It has the folding troy rear battle sights and I want to mount a matching (HK style) front battle sight to it.

Who makes a quality gas block that will let me mount this sight Troy Folding Front Battlesight to it.

I'm not wanting to spend a fortune, but want a good quality piece.

 

[teumessian_fox]

I'm not wanting to spend a fortune, but want a good quality piece.

The two might be mutually exclusive, but you can try these guys:

http://www.yhm.net/ar-15accesories.php

 

[Doxiedad]

Ok let me rephrase. I want good, but not over price, paying for name brand good. Don't want cheap junk, and I don't need top-of-the-line-match-grade-my-life-is-depending-on-this-part-quality.

Gas block Is this the right one?

That one would use the sight i posted above right? Since it's not on the same plane as the rear sight.

Thanks for quick reply

 

[teumessian_fox]

I used these people to set up my S&W M&P 15 Performance Center. They were extremely helpful and carry a full line of accessories. They're also about as cheap as I could find.

Call them and ask them what you need.

http://primaryarms.com/category.sc?categoryId=207

 

[MrCleanOK]

Short answer, yes, those two components are compatible.

Long answer, there are better ways to achieve the desired outcome, but you asked a specific question so I won't get into them.

 

[Doxiedad]

Fox, thanks

Mrclean, could you pm me the long answer? I like to learn as much as possible


Thanks

 

[Tirod]

This can do the job: http://www.brownells.com/.aspx/pid=26844/Product/AR_15_M16_PICATINNY_RAIL_GAS_BLOCK

They also make one in aluminum for less, and it can accept up to three more rails.


And skirting around the long answer to get to the point: What optic will be used?

 

[Doxiedad]

I don't know what optic I will be using. Probably some red dot. I want to get proficient with the iron sights before mounting an optic to it.

 

[Doxiedad]

Tirod, with tha MI block you listed I would need s regular front sight instead of one made for a gas block right. It says it has extra height to mount the front sight on same plane as the rear sight.

 

[Zerodefect]

The rail on railed gas blocks is often lower than the rail on the upper reciever. You need a taller front sight for that setup. MI makes a flip up front sight for railed gas blocks.

I don't see these old setups anymore. The blocky gas block is kinda heavy, ugly, and limits the length of your rails.

You'll be better off installing a low pro gas block, 12" FF rail, and standard Troy/YHM/MI flip sights instead.

So your upper would look more like this:
http://www.bravocompanyusa.com/BCM-...-Receiver-LaRue-p/bcm-urg-mid-16 bfh lt12.htm

 

[teumessian_fox]

Like I said. Call Primary Arms. They bent over backwards to help me and their prices were the best I found. They know everything you need.

 

[Doxiedad]

I'll give them a call tomorrow. Hopefully I'll get to order my rifle tomorrow

 

[Doxiedad]

The rail on railed gas blocks is often lower than the rail on the upper reciever. You need a taller front sight for that setup. MI makes a flip up front sight for railed gas blocks.

I don't see these old setups anymore. The blocky gas block is kinda heavy, ugly, and limits the length of your rails.

You'll be better off installing a low pro gas block, 12" FF rail, and standard Troy/YHM/MI flip sights instead.

So your upper would look more like this:
http://www.bravocompanyusa.com/BCM-1...bfh lt12.htm

I like the look of that, especially with the plastic handguards(?)

over the unused side rails. How involved is installing a free floating rail? Also couldn't I cut down the FSB? Or is there a market for them used if i wanted to sell mine?

 

[Doxiedad]

So for a standard front free floating rail a gunsmith would need to install it right? I've seen a couple of two piece front rails made by Midwest industries. They say you can install them yourself. Can the stock front handguard be removed easily?

 

[Tirod]

No. If it has a standard FSB, you have to drill the pins out, and they will leave holes in the barrel. A lopro block may not cover them up. It's better to spec the barrel as a lopro gas block than buy the wrong thing and suffer the extra expense and labor to change it. At this point, it may be better to think it over some more before shelling out for something that isn't what you really want.

A sighted "free float" with sling mount is mechanically identical to a sighted barrel with sling swivel. It no longer meets the definition of "free float."

Free floats work when the sling is mounted to it, and the sights stay on the barrel. Attaching BOTH to a free float means the sling pressure will affect the sights, pulling them off target and changing the point of impact. Free float tubes generally don't flex as much as a barrel with the sling mounted, but they can and do flex - just less.

If you mount sights on a tube rail, you no longer have the major advantage of a free float - getting the sling pressure off the sight mount. You actually went back to a different version of the milspec setup, for a lot more money. Think about it - then decide why you really want to do that, and if the results still fit your expectations.

If it's a 2MOA shooter, no big deal, it flexes less than issue, but it's NOT better than keeping the sights on the barrel. Don't let the pretty marketing and looks distract you from that.

 

[TonyAngel]

You don't necessarily have to drill the pins out. On most, they will knock out with a punch, but I've had some stubborn ones that had to be drilled/cut out.

Personally, if you're going to free float, do it in a manner that affords you the most benefit. The front sight on the barrel (if you are using irons) with the sling attached to the rail. Since you're going to be using a front sight, I'd just get a gas block that incorporates a flip up front sight and that clamps on, not held on with set screws. Yankee Hill makes decent stuff at a reasonable price.

 

[chrome_austex]

The MI rail height gas block can be used to mount a standard front flip. Its heavy tho.

 

[Doxiedad]

My S&W M&P15A should be here Thursday. After doing much reading I decided to go with some Magpul MOE handguards. I really like the way they look and allow me to mount a light later.

I went to the local gun shop to look around and I really like the HK style front sight. I saw Troy makes a flip up model that mounts on a gas rail block (extra height built into the sight to put it on the same plane as the rear sight) as well as a standard height one if I go with a tall gas block rail.

Either way I'm going to have to use the standard A2(?) sight for a while until I have the money to get the front sights I want.

Looks like optics will be a little further down the road as well, thought I could pick some up for like $100 but after doing much reading and talking to people I think I'll save and get an aimpoint and be done with it.

So either tall block/regular sight or regular block/tall sight?