Happy Saturday folks I'm getting my most recent build rolling and was just wondering what front sight is compatible with one of the trigger cocking NDS uppers? Preferably if someone has a link that'd be great. My barrel is .750" and the build is actually gonna be a dissy. I know this has been discussed to death but I'm incredibly lost on the different heights.

Thanks guys


ETA: above was answered but totally forgot, where can I find the A1/non angled delta rings?

use a standard front sight base.  the F marked ones are meant for flattops.  a .750" barrel isn't retro correct for a prototype but it does give you a lot of FSB options.

Short answer: standard front sights will work.

Long Answer: There are two standard heights for front sights - standard and F marked (there are also several other heights that were used on prototype models, but for production guns there are just the two). Standard non-marked front sight/gas blocks work on carry handle uppers and F marked are for flat top uppers. When the flat top upper was introduced, it was designed by cutting down carry handle uppers. It was shown that this left the upper very weak in a couple areas, especially where the charging handle grove is, so additional material was added to the top to reinforce this area. At the time, the logical solution was to raise the front sight to accommodate this added height, and to distinguish these taller front sights they were marked with an "F".

This can get more confusing if you venture into modern accessories where sights that mount to hand guard rails may be made to work with the front or rear sight of a standard or flat top upper, or different manufacturers, like HK or Sig, may produce different heights to accommodate their products, and some companies just do their own thing and produce arbitrary height sights - usually to address a VERY specific issue such as co-witnessing with a particular optic.

Easy enough, thanks! I just didn't want to order some parts, get everything built, and it being impossible to sight in

And yeah, I know .750" isn't accurate but neither is 7.62x39 and steel lowers

Interdasting, thanks bud!

For the the prototype upper you need a prototype front sight base. I believe JT at rertro arms works makes can make one. It looks like the original ar10 front sight. It isn't cheap, but he makes the correct one. Prototype is the hardest and most expensive to build.  Barrel needs to be a pencil and able to accept a .625 gas block. I would recommend JT for any of your retro work, his work is second to none and turn around time is short.

Slip rings are available at Fulton Armory but are black.

http://www.fulton-armory.com/handguard-slip-ring-early-usgi-excellent-cond.aspx

Flat XM Gray slip rings available through AR15Sport.  I've had good luck with them as well.

When you say "isn't cheap", how much (roughly) are we talking?

Thanks guys! I'll probably go for the gray. Damn expensive things though

If you don't mind black, you can get the full kit for $26.12 on ebay Click Here!

I picked one up from this seller for my latest project and everything is of very good quality.

If you are dead set on an XM grey slip ring, ar15sport.com is the place to go. Great place to do business with.