On stated pressures for any given load, it is like using an engine dyno ... you only have a real base line when using the same pressure bbl or strain gauge set-up or 'dyno', they are not the same otherwise, meaning that you should expect and will receive difs in readings from dif sources. Recall that there are also crushers, strain gauges, LUP's & PSI w/each of those standards of measurement also resulting in expected variances as will individual operators of said equipment.
Velocity difs alone are routinely above 25 fps in the same box of factory loaded rounds and pressure difs are routinely well above that level of difference. This has been written up and reported by professional ballisticians time & again.
I find it very hard to buy into the idea that Remington would have sold even one of those 'black beauty thumpers' if they were over the industry's standard pressure specification. However, those black hulled rounds did have some thump because they were loaded to 3&1/4dram eq. w/1oz of shot. I bought over 7000 of them some years ago and I was quite happy to reach the end of that pile, my perception being that the shooter was being hit at least as hard as the target. There were also some black hulled high brass Remington hulls that had a copper colored wash on their heads and if I recall correctly those were loaded to 3 & 3/4 dram eq. w/1.125 oz of shot! I found neither pleasant to shoot from a standing breech gun.
On soft shooting, it is hard to beat any 3/4oz. load of lead shot at velocities below 1200 fps. Move the velocities up to bunker speed [1350 fps +] and you get noticable recoil.
7/8 oz. or even 24 or 25 grams of shot is quite adequate for dove, if the shot size is appropriate to the task. Keep the velocities within reason and you will enjoy shooting more as other here have stated.
BTW, I'd hope all going out for the dove opener have a great time & in particular the youngsters, like Stan's grandson with his new double and the dogs .. old, four legged or not once again afield to frolic or simply sit & enjoy it.
