Picked up a HW97 today and tried her out. Put on a 4-16x40 Centerpoint and started with Gamo match .177. They are all over the place! Thought well maybe it's the gun, no maybe it's me? The scope? Tried some Crosman super match premier, still all over the place, about a 5" group @ 60 feet. At this point I started to doubt all the good I've heard about the gun.
I bought a bunch of Beeman coated wadcutters a while back and figured what the heck might as well give those a try too. What a shock. How could one pellet be so different? Cloverleaf groups right away; I just don't understand why such a change; how can that be? I was so glad because first moment I picked that gun up is a feeling I will remember; I said "wow" to myself, it felt so right.

pellets of diff weights and head/skirt dia will shoot diff in every gun, try pellets till you find ones you like.
shoot a few hundred first to break the seal in.
Beeman FTS, JSB 8.5 or heavies and Beeman H&N Match should get you started

Differences in the tolerances of parts during manufacturing process, Different batch of steel used, different machine settings, different assembly workers handling the machineries, the result? - different harmonics.
We're glad you were able to find a nice type of pellet for your air rifle ZTob! :thumb::cheers:

Thanks. I just read tne paperwork for the gun and it said tbe first 100 shots could be all over tbe place. Might go tomorrow and get a can of FTS and Crow Mags.