I'll keep recommending (like I have a tendency to do)a couple of videos on YouTube...

for sealing first aid supplies... USNERDOC
for long term food storage... Wendy DeWitt

I got mine to start with some basic long term food storage... put away some basic bulk stores in vacuum bags in 5gal buckets...I've changed after watching the DeWitt video to utilizing the Ball/Mason jar adapter, and dry pack canning in glass...

I've put away some M855 ammunition, but don't see any advantage over the 50cal ammo cans... it's much more difficult to access, and I'll probably load it into bandoleers and repack it to a 50cal can...it might be a good idea to store .22lr in vacuum packs as the bullet is not sealed like most centerfire cartridges...I'd probably use glass for that too...YMMV