You chronograph your ammo to know what the velocity is. How do you know what the pressure is?

There is very little risk in making ammo loaded up to SAAMI specs. How often do you hear about guns blowing up due to over-pressure ammo? In the case of +P 38 Specials being shot in guns not designed for it I have heard of stretched frames and expanded cylinders but not the sort of explosions that would have corporate lawyers worried.

Specialty ammo producers like BB and Underwood have little to offer compared to the big manufacturers except unusual bullets, very small volume niche loadings and most importantly higher velocities. I do not think Underwood and BB could stay in business if their ammo was not more powerful than Federal, Speer, Remington, Sig, etc. They have a lot more motivation to load their ammo a llittle over SAAMI specs than other companies have to load theirs a little under. Without independent pressure measurements there is no way to tell. While every gun channel on YouTube has a chronograph none of them has way to accurately measure pressure.

Before the days of affordable chronographs ammo used to be rated as higher velocity. Those of us old enough to remember reading articles in gun magazines in the 80s all remember statements like "I am sure cartridge achieved its rated velocity in a pressure test barrel but in my gun . . ." as an explanation as to why it was falling so short of its rated velocity. The reduced velocity ratings of today's ammo has more to do with widespread independent testing than it does actual reduced loading.

I don't really know if the extra power produced by Buffalo Bore ammo is the result of big companies loading their ammo below spec, BB going over it or a combination of the two. Unless you have a way to measure pressure neither do you.