I was goofing around with some 190 grain Hornady soft point boat-tails in my old Husqvarna 30-06 lightweight rifle. This rifle only has a 20.75 inch barrel.
These are all with WW plated brass casings.
I tried the following:
58.0 grains RL-22 with a standard 210 primer, COL 3.250 with Lee crimp.
Vel= 2,510 fps 0.67 inch group.
59.0 grains RL-22 with 210 primer, COL 3.250 with Lee Crimp.
Vel= 2,572 fps with a huge 2.60 inch group.
59.0 grains RL-22 with a 215 Magnum primer, COL 3.250 with Lee crimp.
Vel= 2,549 with a 1.0 inch group. YES IT WENT SLOWER??!!!
So with RL-22, an extra grain of powder gained me 60 fps and a huge group. Then a magnum primer was added and the group shrunk while the velocity actually went down....
THEN....I did the same thing with IMR 4350 and the results with the primer change were the opposite as would be expected.
Same as above but:
55.0 grains IMR 4350 with standard primer
Vel= 2,600 fps 0.80 inch group
55.5 grains IMR 4350 with MAGNUM primer
Vel= 2,714 fps 1.9 inch group
56.0 grains IMR 4350 with a STANDARD primer
Vel= 2,667 fps 0.70 inch group.
As you can see, in the case of IMR 4350 the magnum primer added more pressure as expected and reduced accuracy as would be expected in a 30-06.
So what gives with the RL-22 load???