I have a 338 lapua improved with a proof carbon barrel I’m just getting started with. I’ve shot 100 rounds fire forming with it so far (93 gr retumbo 2830fps Berger 300 EH) It shoots great! I took 2nd place at last weeks LR precision shoot, 400-1760 yards with the FF loads. I’m going to start working up loads with ladder testing this week with the formed brass and RE-33 powder. My question is about barrel speed up. Anyone have any personal experience when I can expect it to start, and stabilize with this combination of components? Researching it I’ve found guys talking about other rifles starting from as little as 75 rounds all the way to 350 round counts, others say they never had speed up. I attached a pic of my rifle and the 5 shot group I shot sighting it in.