3 things to consider,
Caliber: 38 and under 13/16 at breech; 45 and under 7/8 at breech; .54 and under 1 inch at breech
style: The earlier the bigger at the breech relative to caliber
Intended use: lighter for hunting if you need to, * to 10 lbs total rifle weight for a serious hunter shooter, Over 12 pounds for shooting from a rest, chunk, cross sticks (prabaly too light or light bend rifle.
You will get lots of help here on the issue
Heinz