I have no experience fire-forming shouldered cases so I would like some advice.  I bought a 219 Zipper Imp High Wall off Gun Broker which should be here tomorrow.  The dealer shipped some reloads separately which showed up today.  There area few different case brands and three rounds that look to be in the process of being formed.  the photo shows one of these on the left.  There was some loading data that said the powder was 33 gr of 4895.  I pulled one bullet and the charge weighed 32 gr.  The unformed rounds weigh about 5 gr less than the loaded formed case so may be 27 gr of powder or so.  My question is should I go ahead and shoot these 3 unformed rounds?  There are also 5 rds that are using 225 win cases.  Thinner and smaller rims that the others.  I understand that Zipper cases can be formed from 225 win so I do plan to shoot these.

Here is as comparison showing the unformed rd.

Thanks

Jack

Pull them. I NEVER shoot unknown reloads. Its just not worth it. Nor will I use powder that I did not open.

I'd agree with everyone else. I wouldn't shoot them. Not that hard to pull bullets and reload them, especially with jacketed bullets you can reuse.

Ok. You have convinced me!   I will start pulling the rest after dinner.   

Frank.  There are 5 or 6 225 cases I will briing them to Spokane and you can have them

Jack

Then I won't feel so bad if I beat you Frank

Keep the 25-35 it works great for forming zipper imp.
LD1

My first rule is safety and don't shoot unknown ammunition.

Next objective for me is obtaining uniform ammunition that's going to perform to my expectations.  Have owned half a dozen rifles that needed formed brass.  All started with fresh cases from the same lot stored together in a single MTM box. It's not worth the time and trouble to load various makers or unknown formed cases.

You probably know all this but,

I would use new 30/30, aneal, then run through a 25/35 F/L then a 219 F/L. Fire form with light charge of Unique. Depending on the chamber may have to neck turn. 

After forming a neck size die with interchangeable bushings or M die are the way to go. Most times I set up with both. Straight necks do fine with outside neck sizers tapered M workers better, cast needs the M. But you may find otherwise. 

Tooling to set up for something that's not factory may cost a couple hundred bucks.  100 new 30/30 cheap.

Boats

what Boats said

but if you can start with .25-35 you'll have a little less brass to squeeze down and it might make the process a bit easier.