Explanation of Co-Witness

[Oscar 319]

The Troy BUIS is good to go. Sight it in and roll with it (or use what came on the gun) until you can afford an EO, Triji or Aimpoint on a decent mount. You may want a 1/3 co-witness, thats what all the cool kids are using these days. I still like my dot on top of my front sight post (true co-witness). No worries, no hurries. Sounds like you have the gun. Go out and shoot the hell out of it and master the iron sights while you are saving up for an optic.

[Chessbay]

The Troy BUIS is good to go. Sight it in and roll with it (or use what came on the gun) until you can afford an EO, Triji or Aimpoint on a decent mount. You may want a 1/3 co-witness, thats what all the cool kids are using these days. I still like my dot on top of my front sight post (true co-witness). No worries, no hurries. Sounds like you have the gun. Go out and shoot the hell out of it and master the iron sights while you are saving up for an optic.

Your right......good advice.

Do I need to be concerned that the top of the rail on the gas block is about 1/4" lower than the flat top rail?

Will this have an effect on sighting the rifle in? Should they not be mounted at the same height?

[BC520]

That should only matter if you have a folding or detachable front sight that is designed to be installed on the top of a FF Rail system. If you post what you have for a front sight that will probably make it easier to clear up if its a factor or not.

[nickdrak]

If you have both front & rear Troy flip-up sights then the front should be mounted on the handguard rail (which should be level with your receivers flattop rail), and not the gas block if it is lower than the handguard rail. A pic would help clear things up.

Otherwise, (Midwest Industries) makes a flip-up front sight which is the proper height for being mounted on a gas block rail:
http://www.bravocompanyusa.com/Midwe...%20gasblk).htm

[Chessbay]

Alright, I hope the pictures work.

Sorry for the poor quality, but when I resized them the quality went down.


So, as you can see from the pictures I don't have a picatinny rail on my handguard. I only have the rail on the gas block, which is not level with the rail on top of the reciever.

I'd rather not buy a new handguard if I don't have to. I'd prefer to save my money for a better optic. Plus I would prefer to not dump tons of money into this gun because it's inexpensive and my first.

So, can I purchase a new gas block with a higher rail? What's the best fix?

[nickdrak]

I would see if you can send the Troy front sight back, and get the MI gas block front sight that I linked above. They will work perfectly together. And you will actually save some cash as the MI is about $30 less than the Troy front sight.

[wild_wild_wes]

If you have a rifle with folding rear AND front BUIS, do you HAVE to use the tall LT adapter?

[Robb Jensen]

If you have a rifle with folding rear AND front BUIS, do you HAVE to use the tall LT adapter?

You can go with either. 1/3 co-witness is my preferred method. That way the sights don't block as much.

[FJB]

Wild,
If using a Micro T-1 on an M4 carbine variant (whether fixed or folding front sight) you'll want to use the the LT66X Tall Riser or ADM Micro Mount with either standard (CO) or 1/3 (SOCOM) Witness spacers. LaRue Tactical is now making a mount for the Micro T-1 that works for HK416s using HK Diopter sights. The new LT660HK Micro T-1 mount is a very nice set up for the HK416 platform. See picture compliments of EAG Tactical.

S/F

[wild_wild_wes]

I like the look of that HK mount, FJB. The lightening holes look like a good idea, even though removing that much aluminum prolly only saves a fraction of an ounce. But I will take your advice and go with the regular tall mount.