It is a snug fit in the Bren chest, left hand side at the bottom. That is the reason for the circular recess cut into the side of the chest. 2 types were available. 1 for ammo in clips and one for loose boxed ammo. But guess what........ You could be sure that if you had a CLIP loader, your ammo would come in loose form. And if you had LOOSE loaders........, guess what? So PDQ the loading machines were put into store because the rifle sections found that they could load magazines, jamb free in a few seconds by hand within a few seconds. Thereafter the TOET was changed to incorporate loading mags by hand and by 91940, mag loaders were consigned to the bin labelled the TWOT bin in forces parlance. Total Waste Of Time