So my .300 upper arrived with a 1:8 twist instead of 1:7

[brutal]

Thanks for posting the extra info.

The supers I've shot from the 9" have been Hornady 110gr factory loads, and from the 16", also the Hornady 110gr or 110gr (V-Max) hand loads.

The 16" is a factory DD upper with a 1:8 twist.

All the subs run through the 9" were either 220gr Rem factory, or 208gr A-Max hand loads.

I've not shot any 147gr through either.