On this stick rigging up for the Normandy drop, you can see that they have a mixture of Thompsons and Garands. All appear to be rigging up to drop with weapons exposed.
when rigged to jump weapons exposed, the weapon is supposed to be slung over the shoulder, muzzle down, and secured to the troopers harness by the belly band of the main chute wrapped over the weapon as seen below
These troopers have their weapons in Griswold bags attached to their harness under their reserve chute.
and while this photo is probably from Market Garden (unless the ground crews have not yet finished painting on the invasion stripes) this shows a mix of Griswold Bags and weapons exposed , M1A1 carbines
the same for this photo (possible Market Garden timeframe), which shows the scabbard for jumping a M1A1 carbine attached to the harness on the trooper in the center of the photo
and here is a Griswold bag with the M1 broken down to fit inside. While it only takes a few seconds to assemble and load after landing, it is still not the best way to jump into hostile territory
I hope this info helps out...
F is for FIRE, That burns down the whole town!
U is for URANIUM... BOMBS!
N is for NO SURVIVORS...
- Plankton
LSM