I have used Wolf Ammunition thousands of times in my "Best-in-the-World", all original and unaltered MI TSMG. The gun has eaten thousands of Sellier & Belot as well. The only difference I have observed is that the Russian cartridges are dirtier........ But in these latest years of manufacture they definitely shoot much cleaner. This weapon is a treasured C&R and I would not do anything to abuse it, always letting others pioneer my concerns first before finally trying things myself. Just another view from still another gunner and collector. Good shooting to you!