The knot in your problem is that you ask about equal pressures and different bores. Pressure and bore has nothing to do with recoil, (or at least it is not factored in any recoil equation I have seen)
If you look for a book maximum (from say speer #13) with a 180 gr. bullet in each rifle, and the same number of grains of powder, you can find these examples.
(We assume the pressures are the same because each is listed as a max load.) recoil # follows vel as....recoil enrgy/recoil velocity
180/308.....45gr/748.......vel/2553.........17/12
180/358.....45gr/RL7.......vel/2728..........20/13
In this case, the 358 will deliver more recoil because the velocity is higher. (pressure same)
If you load the 308/180 and 358/180 to the same velocity you get............
308/44 varget/.........vel/2591...............18/12
358/53/BLC-2/..........vel/2590...............20/13
In this case, the 358 delivers more recoil because the powder charge is greater. (pressure same)
Last example.....a max load w/308 and a starter load w/358 (lower pressure in the 358, but same vel.)
308/41gr/AA2520..........vel/2451...........15/11
358/41gr/RL7................vel/2456...........15/11
In this case the recoil is equal because the bullet, powder, and velocities are equal, despite the pressures being different.
Did this help?? or did I totally dense out on what you were asking??
JimF
