It all starts with a $10 stock wrench from Amazon:
Cheap AR15 Wrench
…note it includes the carbine castle nut wrench (far left) and rifle tube wrench (middle.) We’ll need both.
Get your ghetto vice and stick a short 2×4 in it. Trim the 2×4 so the AR-10 mag-well fits in it.
Ghetto AR-10 Lower Vice Adapter
Now, with the spousal unit holding the un-mounted ghetto vice, turn the castle nut and remove the carbine buffer tube:
Remove the AR-10 Carbine Buffer Tube
Now install the Magpul UBR buffer tube:
Install the Magpul UBR Tube
Now install the UBR top stock with the cheek piece. Simply slide it on and install the screw at the back of the cheek piece that goes into the receiver extension:
Install UBR top stock with cheek piece.
Install the bottom stock:
Install the bottom stock and you are done.
Here’s a closeup of the AR-10 carbine vs UBR receiver extensions:
Carbine vs UBR receiver extensions
Here’s the rifle with the UBR installed:
AR-10 10A4C with Magpul UBR
The result is a vastly improved cheek weld and handling of the rifle. The collapsible stock left a wobbly feeling when aiming. The UBR gives the feel of a solid wooden stock without losing the extensible stock feature.
It’ll likely be standard equipment on any AR rifle I buy/build.