My experience is that pre-WWII ammo(basically anything roll-crimped) is unreliable. I had paper cases fracture and saw lots of confetti, possibly due to fracturing wads. In my samples, FTF's were common and I found some ammo that appeared pristine could be 100% duds.
I saw a marked improvement in post-WWII ammo, essentially any paper shell with a pie-crimp. I attribute the distinct change to the R&D done during the war and the standardization of good primers. I didn't care to shoot anything that appeared to have been wet or otherwise mishandled. However, ammo from the 40's and 50's that appeared case fresh did, in fact, pattern, chronograph and ignite with the same reliability I'd expect from ammo made last year. Grouse flushes are too hard to come by to use untrustworthy ammo yet, For the last 20 years I've used 1950's ammo exclusively for my hunting.
I don't doubt that Tom made the observation mentioned, but I'd be surprised if he intended to make a blanket condemnation of "old" ammo.
If someone were interested enough to pay $5 per sample, I'm pretty sure Tom Armbrust would be willing to test it. If it were me, I'd pick a lot that was visually appealing and dissect a few to see that the shot wasn't fused into a slug by oxidation. If there were no obvious anomalies, I'd send a few over the chronograph onto paper. If the extreme spreads were reasonable and no obvious clumping of shot on paper, I'd send 3 each of a couple varieties to Tom.
