How does IMR 4350 work in a 300WM? I am new to the 300WM and am working on loads for 180 and 165 TSX bullets. I have plenty of RL22 and IMR 4350. I have gotten slightly higher velocities with RL22 but got to the Barnes Manual maximum load without getting very close to the published velocities in either. I think I am going to edge up a bit towards the maximum loads listed in some other manuals to see if I can get a little more zip.
I shot some test loads for the 165TSX today out of a M70 with a BOSS. The manual max for RL22 is 75 grains and is listed at
3143f/s. I got 3045. The manual max for IMR 4350 is 70.5 grains and is listed at 3125 f/s. I got 2984. I was seating the bullets at a COAL of 3.375" whereas the max SAAMI length is listed as 3.34". The rounds chamber at 3.54" but do not fit in the magazine. Would the 0.035" extra COAL be enough to reduce the velocity that much? I suppose I need to try some at 3.34" to see how they do.
I did notice the RL22 loads seemed to have greater recoil than the similar velocity IMR4350 loads. I suppose 4.5 extra grains of powder would make some difference but was surprised it was as noticeable as it was.
With the 180TSX seated to COAL of 3.33 I get 2897 with the manual max load of 69 grains of IMR 4350 and 2916 with the manual max load of 73 grains of RL22.
