I have a Laredo in 7mm STW. It is a 1:9.25" twist. Mine is a 26" non fluted, non BOSS barrel. The trigger is set at 2.5 lbs and is very crisp.
Mine really likes 160 grain bullets of many types. If I do my part, it is .5" or less at 100 yards for a 5 shot group.
I have shot the 175 Nosler LRAB factory loads, and it is about 1" group at 100 yards for a 5 shot group. I did not see any key holing from these.
I believe the 300 Winnie is a 1:10" twist, but not sure of that as I do not have one.
Let me know if you have any other questions on the STW one.