Nope, no sizing needed at all!:)
One thing I have found with vintage guns however, is indexing helps, at times we have run into out of round chambers and such, so a slight file mark at 12:00 always gets them into the chamber with no issues!:
The only thing you will have to do is check your chamber, if it is a 2" or 2 1/4" chamber you will have too trim your cases a bit as they are 2 1/2"
Cat

Thanks! That is really useful information. I will definitely go for the brass shells now. The thing is that I was not sure about the proper size of chamber according to the shell. I have heard that the brass shells offer a more persistent shot!

I have found using a BP measure to be slow tedious and quite frankly a pain in the rear end. Most are aware that modern shot shell presses (I use a lee loadall ) simply do not throw enough powder. So I had a friend 3d print a charge bar that holds 2 shot bushings so now I can throw a square load fast and no spilling.

That is pretty cool!
I honed out an insert for one of my MEC 600 loaders years ago, and used it for throwing the charges and setting the wad pressure as well( the MEC has a scale on it)but have since gone back to throwing my charges by hand then setting the wads by hand for over the powder, then throw the shot charge with the machine and set the wad pressure when I put in the overshot wad:)
I charge 50 at a time and insert wads in.
Cat

I'm using plastic hulls with a fold crimp so would rather do it all on the machine. I will try your method if I ever run out of once fired hulls and make the switch to brass though.

Oh yeah, shooting plastic takes a lot of the work out of it for sure, especifically of you are fold crimping and not roll crimping!:)
There are usually any amount of hulls you can get for nothing at the trap club as well!:)
Cat