Charge bars...what do I need to know? Are the charge bars shot drop specific or are they adjustable? I'm finding shotshell reloading quite a bit different than what I was accustomed to on the Rockchucker.

The bar takes bushings of a size for each type powder or shot. OR, you can buy an Universal Bar that IS adjustable. I have one, well worth the cost. AND, you must match the hulls to the wad for the powder AND shot load. Sounds way more problematic than it really is. You must have a decent manuals, and all that info is in it.

yes , the mech wasn't great for tweaking loads sort of a set it and make lots of ammo

there was a universal adjustable bar however we never had one.

Dad has the Mec 9000G

we new we wanted to replicate Win AA 12ga super handicap 1 1/8 oz of #7 1/2 lead so you looked up and ordered that bar and the bushing for powder that matched the bushing in the recipe book

after that we kept the hoppers full of powder and shot and made a lot of trap loads

the manual for the 600 https://www.mecoutdoors.com/images/...08455%20600%20JR%20Mark%20V%20manual.pdf
bars and bushings https://www.mecoutdoors.com/barsbushingsdies

You will need to either get a universal charge bar or get a charge bar for each shot weight that you want to load. You will also need to get powder bushings for each charge of powder that you want to use. The free Hodgdon and IMR books will show about what each bushing will drop. Keep in mind that there are two different size charge bars. Make sure that you get the one that fits your press. For what it is worth, my charge bars drop on the light side (1 1/2 oz drops 1 3/8oz).

https://www.mecoutdoors.com/images/uploaded/pdfs/PowderBushingChart.pdf


If you are going to stick with one or two loads then a charge bar will be fine but the Universal gives a lot more options and control

I'm going to order a universal bar from Ballistic Products Inc., that seems to be the best approach.
Again, being a complete newbie at this, are hulls from different manufacturers going to be an issue? I can't get my hands on 2 1/2" hulls anywhere so I'll be cutting 2 3/4" hulls down to size.

Are primers going to affect pressure? I ordered a reloading manual for vintage guns so I can't purchase powder until I see what the load charts recommend. That's assuming I can get powder. Bird season is fast approaching and that combined with all of the shortages has me in a real pickle.

Thanks to all of you for the help.

Hulls from different manfacturers, and even from the same one, can make a big difference. Base wad height, composition, hull design ( straight or tapered inside), etc. Get a good, current loading manual. FOLLOW IT EXACTLY. You also need a good set of powder scales to verify charge drop weights. Loads are specific for hull type, wad type, charge weight, etc. What works fine in one type hull can be dangerous in another. A good manual explains all this. Always sort hulls by manfacturer and type. The manual will explain all the different types. A good light and sharp knife to split the hulls length wise will help you understand their diffrrences. As an example--- at one time a hull could have a paper base wad, a poly or poly over paper base wad, a one piece hull (no seperate base wad),and be either straight sided or tapered internally. All from the same manfacturer--promotional dove load, field load, express load, buckshot, etc. EACH DIFFERENT ONE HAD SEPERATE LOAD DATA. Please read that again because it is important. Getting one hull of a different type mixed in when loading can be costly and dangerous. Been there, done it, and it hurts. Costly too if the gun is repairable. Adjustable charge bars are nice. The bushing type bars are good too, but you usually need a couple of bushings either side of the one called for to dial in the powder weight. Operate the press with the same force and speed every time you pull the handle. Even with the baffled powder bottles the vibrations from operating the press can cause variations in powder drop weights. Some powders are not very forgiving and things can get out of hand fast. Changing any component causes pressure changes. Sometimes a little, sometimes a lot. The manual should explain all of this. How all the components work together and the effects of changing them applies to any shotshell. The basics are the same reguardless of gauge, length, etc. If you can't find a manual for the short shells you are wanting to load then a manual covering all the normal lengths will give you the basics for safety, component ID, etc. Then you can find the "recipes" elsewhere.