It should be, but the inside probes on calipers are notoriously unreliable for holes. Nothing with a flat edge works in principle, and having them report two thousandths smaller than reality isn't unusual. If .357" bullets fall in, then they are actually bigger than .357". No two ways about it. Calipers being off a thousandth even with the OD jaws isn't uncommon either. For measuring bullets and the small hole gauges used to make transfer measurements of the insides of holes, you need at least a
thimble micrometer with a ten-thousandths Vernier scale. For a couple bucks more, a
mechanical digital is available at Harbor Freight. If you intend to slug bores to size bullets, or do other critical measuring, forget fighting the caliper and get one of these. Just don't forget to wipe off the anvils and check for zero offset. There are usually a couple ten-thousandths error at zero that you need to add (if low) or subtract (if above zero) to your final reading.
As to the brass, yes, alas, this is typical R-P brass behavior. I found it with .45 ACP years ago. The walls were too thin (thinner than Winchester BTW) and the stuff could be reloaded maybe two or three times before it work hardened and got so springy, you couldn't size it in a standard die. It's not worth the time or effort to try to figure out how to safely stress-relieve cases as short as pistol cases. I recommend you bite the bullet, or, in this case, the case, and get yourself some new
Starline brass. It's made to tighter tolerances than what you have, will reload well and last through more reloads than you need to justify the price. It's just under $70 for 500 and $120/1000, S&H included. Some vendors, like Midway, break it out into 100's, but they charge for that service and clobber you with S&H, so it hardly seems worth it unless you are ordering enough of something else from them anyway to use one of their 10% coupons.
Starline says most of their brass does not require resizing all the way to the head, with the exception of .454 Casull. They recommend you only resize to the seating depth of the bullet (for maximum case life), but I've had no issues FL resizing it in .45 ACP.
Scharch also makes good, high tolerance brass (Top Brass brand, but don't confuse it with the used brass company calling itself Top Brass) when they have it available. It's equal to Starline, but costs fractionally more, plus you need to order $150 or more to get free shipping.