I was shooting some 38 special handloads and was getting velocities about what I was expecting from them, 700fps or so.  Then I took some of these PPU 158gr SWC 38s and the five shot string was 1648 1638 1628 1625 1622.  WTF?

I haven't been able to pull one and check the powder load but doing a weigh in and subtracting the bullet and case I was left with around 4.4 grains.

These definitely felt a lot hotter than my hand loads but this has to be a chrono error right?  But all 5 shots were in the same ball park. I wouldn't expect that from a .357 load with that weight bullet.

Shooting in daylight with a Gen2 Caldwell chrono, the upside down one.

Yeah, that seems way too fast for a 158gr projectile, IMO.  I think the only way to verify is to use another chrono.

I lack access to one unfortunately.

How did the cases look? Sticky ejection?

I bet chrono error, that is smoking fast.

Cases looked fine.  I'm just curious why I was getting decent results from my hand loads but these were all crazy fast.  Am I shooting at a bad angle?

Move the screens out another 5 feet or so.  I was getting similar velocities from .357 158 gr reloads…out
Of a 2.5”….yeah, not happening. Moved the screens out a bit further the velocity’s came down to 1200ish.

No way 4.4 grains of powder is pushing a 158 grain bullet to 1600 fps.     I have a load worked up for 158 grain Hornady XTP bullets that takes 16 grains to get 1800 fps from my 16" barrel Ruger 77/357

While I am not a reloader , I did notice that the PPU 158 FMJ was HOT as hell out of my 6" 686 no-dash. The primers were flat, although I can't remember if there were issues with extraction.
maybe they rated at the European CIP rather than our SAAMI spec?