Not mine, but he's using a Thorntail keymod/1913 adapter. Pretty sweet set-up.
Here's a thread where he started the project:
12.5 SBR build
Upper-
Sabre Defence 14.5" barrel cut to 12.5" and threaded to 5/8"x24
BCM blem receiver
AA hard use bolt (unsure of carrier manuf.)
BCM MKR10 handguard- REALLY liking this one- super light and great profile. Seriously considering switching everything to it.
Micromoa Govnah switchable gas block
YHM QD break for the Ti 7.62 can
MI keymod grip panels
PRI Gasbuster charging handle
Optic-
1-4 VX-R ballistic firedot in Larue mount- Still undecided if this is going to stay or go to a 2-7.
Lower-
RRA SBR'd receiver
RRA NM 2 stage trigger
Magpul CTR stock
Hogue ghillie tan grip
BAD lever
8.7 LBS as it sits in the picture. 9.7 with 25 rounds in the mag.