I had a nice load for my 200gr partitions in my 300 wm with retumbo and recently bought another 5lbs as I was out of my other stuff (bought 4 years ago). The new 5lbs is all the same lot number. My old load was 84.8gr which worked perfectly fine at 0C (last time I chronographed and shot it). I figured I would start lower with the new stuff so I started at 80gr and went up in .6gr increments. I got ejector marks at 81.2gr and had to use a dowel rod to get the case out at 81.8gr. Nothing else changed, same primers, brass bullets seating depth etc. It was +6C when I fired these rounds today and the rounds were in the back the truck so they also were ambient temperature. I checked my beam scale with check weights and it's bang on. I have shot up to 86gr of the old retumbo with only the slightest ejector marks but I don't think I will be able to go higher than 80gr with the new stuff, especially once it gets a bit warmer out. Anyways, I'm sure you all know to start lower with new powder and I always do, but I have never had a spread this large before difference before.
Retumbo != Retumbo
- Thread starter kman300
- Start date
I have heard of Retumbo having serious issues with lot-to-lot consistency from several different sources; both word of mouth and online.
It's the reason I've avoided it for my .300WM and stuck with H4831. Slightly less velocity with the heavier bullets but I'm okay with that.
It's the reason I've avoided it for my .300WM and stuck with H4831. Slightly less velocity with the heavier bullets but I'm okay with that.
