Shot some IMR 8208 XBR in the 338 Fed yesterday. No chrono, but accuracy was the best across the board I've seen. Was with 180 BTs, 200 Hot Cors and 185 TTSXs all with Fed 210 Primers and Federal brass. Also tried some 200 SSTs with H4895 and 210 primers. Accuracy had been so-so with BR2s but was fantastic with the 210s. Food for thought.