So I just bought an AR, a M400 Tread. I need to get back up irons to work with whatever optic I get. While there’s a standard rail on the receiver, the front will have to go on a M-Lok rail at the front of the forend / hand guard.

I’ve always been partial to the Magpul back up irons, but will they work with the Tread setup or be the right height.

Thanks for any help / suggestions.

https://www.sigsauer.com/sight...lok-screws-nuts.html

This piece should allow any matching BUIS tandem to mount at the same height. Now sure if there are any 3rd-party options available, but in the past I've been told by Tread owners that the SIG part does the job.

Well, ain't that typical Sig corporate BS. The M400 is a decent rifle, but I've never liked the handguard on the Tread. Now I like it less. How hard would it be for them to throw that rail segment (that probably cost them all of $3 to produce) into the box with the rifle? Instead, they're jabbing any customer that wants a front sight for an extra $30...and that's not even for a front sight!

Better get it now because within 5 years it'll be discontinued in favor of some other proprietary handguard design, and you won't be able to find one anywhere.

https://www.samson-mfg.com/m-l...g-sight-package.html

These guys make an M-Lok front but I can't see that they sell it separately.

So I got the M400...here is the before...







I bought a few bits and pieces...





After...