Reloading cartridges in the field is something that has been done by hunters and partisans for as long as we have had firearms. Modern soldiers and sportsmen have access to seemingly unlimited supplies of factory loaded ammunition, but handloading ammo while in the field is still a great skill to learn. You never know when the zombies may show up, or the Cubans paratroop into your town (see: Red Dawn).
For handloading while on the move, there are two kits made by Lee Precision that fit the bill. They both work, and both are inexpensive.
The first option is the Lee Loader. The Lee Loader is a simple kit that contains everything you need to reload a single caliber (minus the components: powder, primer, bullet, brass). This kit allows you to use a hammer, rock or another heavy object to decap, resize, seat a new primer, add the powder and seat a bullet in about 30 seconds.
The Lee Loader system is easy to run and is inexpensive (street prices less than $40). All major pistol and rifle calibers are available including a number of surplus calibers (such as the 6.5×55 Swedish and 7.62x54r).
The second option from Lee is the Hand Press. The Lee Hand Press comes as a small kit to which you will have to add dies. Fortunately, the Lee die sets come with powder dippers (measures), charge tables and shell holders. This means you do not have to add any additional gear to the shopping list.
The Hand Press and dies take up more room than the Lee Loader, but it does give you more flexibility in calibers and loading. The Hand Press accepts all typical rifle and handgun calibers.
The current generation Hand Presses are set up to take the Lee Breech Lock bushings. This allows you to lock your dies into the bushings at the precise measurements you want to use for seating depth, etc. The bushings then quickly lock into place on the press without the need to screw the dies in. I have the older, non-breech style Hand Press and highly recommend the newer breech lock style.
Hopefully, you never find yourself in the position of melting down your child’s lead soldiers to cast bullets to fight enemy soldiers (see: The Patriot), but with either of these kits, you could reload that ammo. Locating primers is a whole different story.