I have had a similar experience with Hornady (only mabey more extreme) I love Hornady bullet's for varmint hunting because they are accurate and explosive because of their proprietary copper-butter jacket, but a couple years ago I was out shooting through the chronograph with goodgrouper testing loads for my 7mmRemMag. I tried several different powder's and seating depth's with 2 different bullets The 160gr Accubond and the 154gr Interbond.
After the first test I had to get a bigger 100yard target to accurately measure the groups. the 160gr Accubonds were not stellar shooting around an inch to inch and a quarter but the Hornady 154gr Interbond shot around a foot to a foot and a quarter. I tried 3 different powders and 3 different seating depths and never shot 1 group under 12" (yes that is a foot) worst bullet EVER. I was unlucky enough to buy 200 of the same lot and still have 75 left if someone else needs a laugh LOT# 04-022
UB
After the first test I had to get a bigger 100yard target to accurately measure the groups. the 160gr Accubonds were not stellar shooting around an inch to inch and a quarter but the Hornady 154gr Interbond shot around a foot to a foot and a quarter. I tried 3 different powders and 3 different seating depths and never shot 1 group under 12" (yes that is a foot) worst bullet EVER. I was unlucky enough to buy 200 of the same lot and still have 75 left if someone else needs a laugh LOT# 04-022
UB