Mystery 0.50 Cal. WWII ammo chute

Hello – can any bright spark ID this please? It’s quite a large assembly – It could be American – seems to fit a 50 Cal machine gun. The main body would fit under the weapon and the cartridges would fall out of the bottom of the gun. The spent links would also be fed into the main body by the curved chute.

The chute has the part number ASSY 80921 C-26, the body has 80090-R

It came from a dump of British and US WWII aircraft parts last year.

Can anyone ID it please? Possibly from an American turret? We also found B-25, P-51 link chutes and some US turret parts.