I recently had good luck with the 185 grain TTSX using a medium charge of RL17. Rifle is a Sako AIV .338 WM that, after a bedding job, does about MOA (sometimes better) for 3 shots out to 385 Meters on steel.
I had a good bit of RL17 left over after switching to a different powder for another caliber. Barnes also shows RL17 as their most accurate powder with the .338WM.
I found an accuracy node from 68.0 to 68.5 grains and stopped there since I was only looking for 2,900 fps or so.
The final load is 68.2 grains of RL17 in older Federal Nickle Plated brass using a standard Federal 210 primer. This brass may be heavier than most, btw. I have some new Nosler brass on order.
COL is 50 thou off just touching the lands.
When working up the load I was initially using the suggested Remington Magnum primer, but the F210 lowered the SD from 21.6 to 10.2 and increased the average velocity by 18 fps - to 2,908 fps. I'm using 2,920 in my ballistics program for the 68.2 grain loading.
I think the barrel length is 22".
Chrono is a MV3 Magneto Speed. I was loading 68.0 grains when chronographing in July, and switched to 68.2 last fall after re-bedding the rifle. It would previously shoot great with a warm barrel, but has always had the tendency to throw the first shot a little high.
After glass bedding, I'm now getting POA=POI from a cold (dirty) barrel.
RL17 can be temperature sensitive and I know this is true from some early 6.5 Creedmoor loads that were worked up in cool weather.
I have not noticed anything pressure wise with the .338 WM loads, but I'm well below maximum book load.
I running 71.5 of RL 17 with 185 TTSX in my 338 Win. This is probably the upper OCW. I normally use IMR 4350 @ 71.0 with 225gr Swift A frames with great results. But I thought I would give RL 17 and 185 TTSX a try for moose.
Hello Milan, I just watched your video on disassembling/reassembling the CZ 550. I have spent days looking for something like this. I now have no reservations taking apart my rifle. I like to do this with all my guns so I understand them "inside and out". Thank you very much for the information. It is greatly appreciated.