What are the bolts on the side of the B&T APC223 for?

[Kano]

I am considering a B&T AG APC223, I see that there are 4 Torx head bolts on the sides of the gun. What gives? What are these for?

Seems odd that something with such a high level of engineering would be built this way.

 

[onetwentyish]

Safe to say its for securing the barrel, trunion, or forend, or possibly a combination of the 3. I will post back when I recieve mine later this week.

 

[Twan]

They are for securing the trunion to the extrusion. You can see they use the same method across most of their newly released subguns, and full size rifles. It is done the same with the FN SCAR - the 2 black wings you see just forward of the ejection port (and opposite side) are where the screws mount to hold the trunion.

 

[onetwentyish]

They are for securing the trunion to the extrusion. You can see they use the same method across most of their newly released subguns, and full size rifles. It is done the same with the FN SCAR - the 2 black wings you see just forward of the ejection port (and opposite side) are where the screws mount to hold the trunion.

Exactly, the same is also notable on the ACR

 

[MPI]

Can you swap change barrels and fore stocks on the APC223?