Was having difficulty getting my 1897 vintage .38-55 M94 to group consistently, having a keyhole every 5th or 6th round shooting hard cast .380 gas checked bullets. BBL slugged .380. Have fired approximately 30 .381 sized Rim Rock bullets over 10.5gr of Unique. Average 2.0 inches at 75yds. Best is 1.5in three shot group. No flyers, no key holes. Got a box of .376 commercial reloads with gun years ago and, due to key holing at 25yds, it has been in the back of the safe until recently. Rim Rock provided quick shipping and excellent packaging. Thanks, Robert