You have some unique rifles, for I have 5 reloading books and only one gives data for a 50-70 (government), and nothing on the 40-90. Curious, do you use lead bullets?
"ABC's of reloading" is highly recommended by many and I would recommend it as a first read. Lyman has a pretty good book, and includes data for 50-70 gov. Hornaby, Speers, Nosler, and Sierra (to mention a few) also have good books, and I try to choose my books by the bullets I use (but thats just me).
Regarding reloading equipment, start checking out your local gun shops to see what they have and what prices are like. Lee, Dillion, Hornaby, RCBS (to mention a few) all have single stage press reloading packages that are quite reasonable. Not thinking you need anything fancy for the small volume you are talking about.
I would also look into to what bullets the local gun shops stock/carry and this may help you get load data and decide on what bullets you will use ... and powder recommendations might be able to be obtained from the bullet manufacturer. I'm thinking you wont have a big selection of bullets to pick from, due to the calibers.
for equipment, in general, you will need:
- a press - single stage would suit you well
- most presses or kits don't come with a bullet holder or dies, so you need to get a bullet holder and a resizing die set specific to your caliber. Not exactly sure of you shell configuration so unable to tell you which die set ... 2 or 3 piece .. you need.
- brass cleaning tools (primer pocket brush, neck cleaning brush, deburring tool, and a flash hole cleaning tool). Many packages come with what they call a cleaning center, which includes all these, but for your volume not really required.
- case trimmer and calipers
- case tube and and a brush to apply lube to inside of neck
- primer removing and installing tools. Alot of presses have this built into the press, so you may not need to purchase seperately.
- brass cleaner, such as a tumber or ultra sonic cleaner. I really like the ultra sonic cleaner for it is fast and does a very good job (just remember to wash off your shells with warm water and baking soda after ultra sonic cleaning (otherwise the brass will tarnish).
- powder measurer, alot of packages will come with a beam scale or an electronic scale. I use the RCBS chargemaster, which is an electronic scale that automatically wieghs and dispences the entered grains. A beam scale would suffice for your needs if you want to keep the costs down. I would avoid "cheap" electronic scales.
- trays, for holding your shells during the reloading stages.
- work space/bench and lots of PATIENCE.
Note: most components ie dies do not need to be manufacturer specific. ie you have have an hornaby press and use RCBS dies.
to reload, I follow this process.
- lube the outside of the shell and the inside of the neck (using a wire brush) with case lube. It doesnt take a lot, use sparingly, and avoid lube the outside of the neck as much as possible.
- install bullet holder into press
- install Full length resizing die into press, and resize and remove primer. Alot of presses will do this at the same time. (i use bottle neck cases so I use a 2 piece die)
- trim shells to length, using a case trimmer and calipers. Reloading books will state the trim to lenght.
- clean brass using a tumbler or ultra sonic cleaner and let dry. Air dry, best not to use oven for you can over heat the brass and reduce its life.
- clean primer pocket, remove burrs, clean inside of neck and flash hole
- install primer. Most presses will do this.
- put shells in tray and measure out powder and fill shell.
- install bullet seating die, put loaded shell into bullet and place bullet .. then seat bullet.
- measure the overal lenght of the bullet using calipers to ensure you have correct length, which is provide in most load data.
- inspect loaded shell for craps, dents, proper primer seating etc
- check to see if will chamber in your gun .. if yes you are good to go .. otherwise adjust seating depth.
Always check you brass and final bullet for quality and defects.
The above is minimum, and you can get other tools to fine tune your bullet such as OAL guages and head space gauges ... but that all comes one the basics or mastered.