Good Day! The prophet P1 comes with a LR22 barrel 1:32 twist that shoots jsb redesign really well, at a good speed as well, 950 fps down to 880 fps. the barrel and redesign pellet were kind of developed to work together. I promise you would not be disappointed!
The P3 has a RPB barrel 1:16 twist which also likes the redesign but at 920fps or slower, but likes slugs also. The P3 has a assisted air valve which makes tuning a bit easier. you can get a LR22 barrel for it as well. so when I'm comparing the 2 guns here it would be with both using the LR22 barrel.
The P3 is more efficient than the P1. The P3 only needs 115 bar to reach 945fps. where as the P1 needs 130-135 bar.
Both guns shoot just the same with LR22 barrel and redesign. I get the same groups. The mora as well with the LR22. The mora only needs 90 to 100 bar with LR22 barrel.
My honest opinion if your just going to shot pellets go for the P1 with the redesign. I have my P1 performance tuned at 130bar and hammer adjusted to get 945fps. SD 1.6 and max of 7. the only modification I have is the dual regulator from RTI. The P1 never lets me down.
I have seen the prophet shooting the redesign at 1040fps. Impressive grouping at a 100 yrds. I find though, I get flyers every 5 or so shots. The gun is pretty hot at 180 bar and hammer turned up to get this speed.
hope this helps
Dyno