I've got an old ruger m77 in 7mm rem mag, I just got back into reloading last year. I didn't have enough time before deer season to do any serious load developing for it. It wasn't the only caliber I was loading for.I loaded some 140 grain accubonds and the best I could get them to group at 100 yards was maybe 3 inches. Like I said, I didn't haveenough time to change different componentsso I bought the deresonator, put it on, and the groups shrank to 1 1/2 inches. Nothing to brag about, but good enough for me to hunt with this past season.