4 years in september with RL-17 in 6.5x55's and 7.5x55's. I was looking for a powder that would be accurate of course and was told this powder had a gentler burn with less pressure problems for my old Swede and Swiss rifles. I know that these aren't what you were looking for but I have got accuracy on paper at 100yds with both calibers and iron sights that are amazing. My shooting is usually 40 degrees and up and I have not seen a change in my groups that would warrant me going back to other powders.