I am going to work up a load using Weatherby brass, CCI 250 primers, RL22 powder and 165 gr. Barnes TSX bullets.

I have consulted a number of reloading manuals and data sources, all with varying numbers as to maximum powder charge. They range from 82.5 gr. in Barnes #1 manual, to a maximum of over 87 grains in Hornady data!

As usual, I work upwards, but this great variation is puzzling.

Any practical experience with using this combo?

I tried the Reloder 22 & 25. They both produced sub-par results with too many unexplained fliers. Desperate for some answers and frustrated after 400 rounds down range without anything to show for it except an empty pocketbook, I got a tip from a fellow 300 Wby shooter to try 84.5 grains of Imr 7828 and switch to 180 gr bullets. I took the advice and the first three rounds fired from that combo went into 1/2". I have worked on three or four different 300 Wby's since then and I have yet to have that combo fail, or at least a grain +/-.

I shoot:
180 gr Accubond
84.5 Gr Imr 7828
CCI 250
Average 3200 fps & < 1 moa

You may find success with 165's but I could not with my Encore. After I switched to 180's in my gun I never try anything else when working with other 300 Wby's.

That is a rather large disparity in maximum loads to be sure.

However, the Barnes #1 data was created using the old Barns X bullet, not the TSX version. The newest Barnes manual (#4) shows a maximum load of RL 22 in the 300 Wby Magnum when shooting 165 or 168 grain bullets of 87 grains.

However, I found I could not safely shoot 87 grains in my Remington 700 Classic chambered in 300 Wby Mag. With the 168 grain TSX I found 86 grains to be maximum in my gun.

I prefer to shoot the 180 grain Nosler Partition in this gun, having shot everything from coyotes to 6X6 bull elk with that load. However, I had to find a subsitute for use here in California due to the dumb ass no-lead law in effect. I dropped down to the 168 TSX just to try it and have gotten very good accuracy with that bullet and RL 22, some groups as small as 0.274 inches! Just a fluke to be sure, but most groups are around a 1/2 inch. I have not shot any game with this bullet yet, may have to try it on a wild hog here soon.

85 RL-22 with Weatherby brass, Federal 215s and 168 TSXs achieved sub-moa and about 3300 fps out of a 26" barrel for me.

I loaded up several different powder weights this AM, and went to the range- not too crowded today! Temp was 20 degrees, but no wind.

The last load shot was the heaviest powder weight, 82.5 gr. Chrono velocity was 3235 fps, and it shows some accuracy potential, as well. Cases show absolutely no signs of pressure, and this was a very pleasant round to shoot, as .300 Wby rounds go- noticeably less recoil than some of the 200 gr. loads I have been shooting.

Will try another half and one grain increases, if I get to 3300 fps at decent air temps and good accuracy, I'll be happy.
Doesn't look like it will take anywhere near 85 gr. to get there.

FWIW- a half grain powder increase gives 35 fps increase in velocity, at least it did today.