The Pelican Storm Cases iM3300 Long Hard Gun Case can be purchased with foam included (MPN:IM3300-30001 and MPN:IM3300-00001), or without foam (MPN:IM3300-00000).
The Pelican Storm Cases iM3300 Long Hard Gun Case has interior dimensions of 50.5" x 14" x 6.0", meaning you could absolutely fit two full size AR15 rifles in this case. The Vault V800 has an extra 2.5" of interior length and 2" of internal height, meaning it will better accommodate two rifles especially if you have LPVO's or scopes mounted to your AR15's. Either or should work fine but I would lean more towards the V800 if you have, or are planning on using an LPVO or scope on your AR15's.
You'll want the model iM3300-00001.
The interior dimension for the Pelican iM3300 case is 50.50" x 14.00" x 6.00" (128.2 x 35.5 x 15.2 cm). If you choose the model that comes with foam, it will have standard multi layer cubed foam.
The internal dimensions are 50.5"×14"×6" and the weight with foam is 23.00lbs (10.4kg). The weight without the foam is 19.10lbs (8.7kg).
Foam is not included.