Mike, "to the range with a single cartridge"? I do not go to the range with a single rifle, more times than not I go with 10 rifles, with 5 of them Mausers in 8mm57 or M 1917s chambered in 308 Norma mag., 303 British 30/06 etc..
I determine the effect the chamber will have on the case when fired, I do not fire first then determine the effect the chamber had on the case.
I start reloading by using cases that is too long to chamber, I do not waste my time going to the range and fire form, I form first then fire, after firing formed cases I get once fired cases.
As to the model 38 and case head separation, there is a technique/method that can be used to determine if the potential of risk of case head separation is possible but when discussing these matters the first response is 'Hatcher said". not easy to get past that on the Internet, but in the real world it just takes a few minutes plus mileage.
Again, I was told I was wrong, a man built 5 rifles using Remington 03A3 rifles, he made the reamer and built 5 magnificent rifles chamber in 7mm, when he attempted to fire form brass, 4 of the first 10 cases ripped, split and or separated. I ask the builder of the rifles to tell me everything he knew about the 03 type Springfield, when he got to "and that is it" I told him I could have told him what would happen before he left the shop, I told him if he had a problem at the range I could have fixed the problem long enough for him to form h8is cases, I told him I would have formed the cases before I left for the the shop, he then informed me he did not form first but did use another method.
F. Guffey