A few weeks back, someone in the equipment forum had a mount for sale that mounted to the barrel of an M4 via 2 ubolts, allowing you to forward mount optics. After setting the ubolts, you replaced the handguards and then a small weaver mount (similar to Adv.Arma.'s mount) attached to the top of the ubolt set-up.

I can't recall who made it or find the original post. I didn't buy it at the time because I have a full profile heavy barrel and this only fit the M4/thin profile barrels. I wanted to look and see if the company made any other versions of this.

TIA

*bump* 1

He'ps!

Don't know but..... make your own.  Gun shop for the Weaver mount and hardware store for the bolts / nuts.