That's interesting to hear
I opted to go with the .30/30 AI, thinking that larger capacity wildcats would be shortening the life of the gun by creating stretch in the frame.
It sounds like it might be smart not to load to the max, because the 30/30 AI is probably topped out, as far as how powerful I can go.
I will be headspacing off the shoulder which leaves a tighter clearance (0") than the headspacing before fireforming, which was about .006"
So maybe case stretch happened in fireforming. But I measured before fireforming and after and the cases were shorter, not longer, as they ought to be.
But whatever the case with that, after fireforming, the gun snaps shut tight with an interference fit between the breech and the back of the case.
Before fireforming, the back of the case was below the back surface of the chamber, by about .003" and after fireforming it's higher by about .003" So the case is not longer but being headspaced back .006" further by headspacing off the shoulder as opposed to the rim.
I did some business with Mike Bellm Sr and read a few of his lengthy articles, and he explained some of the things that I didn't understand through reading.
So I believe I'm doing this right, although I'm not able to perform scientific tests any further than measuring cases.
I'll add to this: Reflecting upon my original reason for wanting to chamber a Contender barrel in .30 cal to begin with...
I wanted a handgun that is capable of 250 yd max range, for use with Barnes lead free projectiles, for hunting in CA and I decided on .30 cal because of the number of bullet choices.
The lead free bullets are typically longer and require deeper seating to allow the recommended free-bore before engagement into the rifling (IIRC .050"-.080")
So with the added seating depth consuming case volume in the .30/30, the AI seemed like a good choice.
When I had it reamed, I sent it out to David White and he did it right, but he gave it a longer throat as well, so now I can seat a bullet a bit further out than the original chamber permitted.
I have some Barnes bullets that are intended for .30/30 velocity for use in a tube mag lever rifle... Flat nose 150 gr - unimpressive BC but effective down to 1700 fps. I also have some 130 gr Barnes rifle bullets that I need to experiment with.
I have some LEVERevolution powder, as well as some 4198, 4895, 4064 and 748
So if anyone has some useful data to share, I'm listening