Nothing wrong with the factory ammo, sometimes you have to try 5-6 different brands to find the right combo...My gun loves CoreLokts, Federal Premium Nosler Partitions, Winchester Supreme PowerPoints, all in 100gr...

It doesn't care for the 95gr Fusions, 95gr Winchester Combined Technology Ballistic Tips, 100 gr Custom Hornady InterLokts...

Just need to shoot several and see what it prefers...

That short, light barrel on the Model 7 does heat up fast, which will also affect your groups...I have 2 buddies that have them in the 7mm-08 and the .260, they shoot fair, but not great.