HPS in Gloucester stock the Muroms. As a previous poster said, the large rifle are very good, the small rifle magnums can have difficulty igniting certain powders in the larger cases with small primer pockets. 6BR, no issues with any combination. 6 x 47, SRM Muroms & N560, hangfires every time, CC1450's cured that. Yet with N550, a much smaller granular powder than N560 they were fine. I just think the Muroms of any persuasion are very mild, it just doesn't seem to be as big of an issue with the larger primers however.