I have about 10 years of experience loading rifle and pistol, but I have never played around with shotgun.

I am interested in mostly playing around with .410, but there are just some things about shotshells that I don't get.

It seems more difficult than metallic.

So you can't just match shot weight X to powder load Y?

You have to have the exact hull and the exact wad the load calls for?

Is this just for the sake of everything being the right length in the end?
Or can you just trim the hulls and make any work?

I mean 1 oz is 1 oz right? Whether that be slug, buckshot, bb shot, or #8
Wouldn't the pressure be the same?

You do need to follow recipies.  Exact hull, primer, wad, powder.  Take a little time and compare some loads with nothing but one component changed and look what it does to pressure.  Spend some time looking at hodgdons site, pick a hull and look at the data.  Something like Universal Clays will have data for multiple wads and primers and will show pressures. SAAMI pressure for .410 is 12,500psi.  Good idea to stay below that as a reloader, maybe 11,500 psi for a load, that gives some wiggle room if you have drop to drop powder variations, or your crimp is too deep, or your shot drop isn't accurate.

A 1oz slug isn't the same thing as 1oz of shot.  The shot column can constrict going through the forcing cone and the choke while a slug can't.  Different internal ballistics entirely.

You don't get pressure signs with a shotgun like you do with metallic.  The weak link is the chamber or barrel, not the primer or case.

It isn't difficult, but you do have to play by the rules.

One problem you'll have, especially now, is trying to find components for the load you want.  Do not go buy what you can and then try to find a load for it.  Find a load, then go find components.

.410 can be especially tricky because it is very sensitive to stack height.  You have to have it right or it won't crimp well.  There is very little forgiveness in .410 loading.  The best hull by a large margin is .410 AAHS winchester hull, a distant second would be Rem STS.  Most of the other hulls are load once and throw them away, you'll get a lot of failures where the hull separates from the base even on the first load.

For .410, 1/2oz target loads, try to find h110/w296 powder or lil' gun. AAHS hulls, and I prefer the Rem rxp wad.  I use a primer you're not supposed to use for .410, so I'll tell you to use Remington 209 primers or Win 209 and leave it at that.

The above can't be stressed enough.  

One other thing to add.  Internal hull dimensions and base wads differ between hulls.  That's another reason why you need to follow the recipes.

When all the old brick and mortar retail stores left SoCal, it became very hard to get shotgun supplies for me without crossing the county.

I tended to rely on mail order and that became web sites.

Some web sites are worth learning about because they are a repository for manuals and recipes for the types of things they sell.

Here is one I have found useful for non-tox shells that I must use for waterfoul and now even for general hunting and coyotes.

https://www.ballisticproducts.com/Manuals-Brochures/departments/272/

https://www.mecoutdoors.com/shotshell-reloaders

Get yourself the best loading books and manuals you can find and read up before you go too far. Get with an experienced loader if at all possible. You will learn faster from a mentor than any books or videos.

Just know that about 90% of what you know about metallic reloading does not apply to shot shell reloading.

It's the same kind of concept, but totally different.  No where near as precise.  No where near the data that is available for metallic reloading.

I would say that it's EASIER than reloading Rifle cartridges.  maybe a tick harder than reloading Pistol cartridges.

-Masta

I was in the same boat recently. Started playing with some gifted components & MEC equipment. Also found

the 600 jr. I loaded with as a kid. Now I knew the load process when I was doing it as a young teenager long ago,

but I didn't really understand the specifics. I picked up Lyman 5th Edition and read through it like a newbie.

It really helped. I'll be loading 28 gauge as well as 12. Good luck

444 marlin cases work excellent. So don't pass them up if you can find them cheap. And they will last 20x as long as a plastic case. And you don't need any plastic wads either. Use a nitro card and fiber wads for the stack then a over powder card and use a 308 seater die adjusted to put a slight roll on the mouth.

Ed Harris showed me this.

wrote this over 10 years ago

still relevant.  Photophucket stopped hosting the pictures but I've found them and started to rebuild the posts

https://www.ar15.com/forums/armory/The-12-Gauge-Shotshell-Reloading-Tutorial-DONE/42-299960/