I think I’m going to try to start a thread even better than this one.
The central question can be: from a load development and reloading perspective, does anything have an affect on accuracy other than velocity consistency and projectile consistency.
Yes. In fact I would say velocity consistency is less directly linked to dispersion than a long list of other things.
A start to a short, completely non-inclusive list,
Bore and groove diameter consistency
Bore and groove diameter ratios
Bore and groove area ratios
Bore straightness
Bore/OD concentricity
Throat geometry, especially combined with bullet seating
Case clearance/chamber geometry
Bullet/groove diameter relationship
Bullet rigidity
Powder type
- A muddy mess of discussion on pressure vs. time or pressure vs. distance curves
Muzzle device
- Tuners? suppressors? Mass? Gas flow?
Rifle weight
Bedding
Barrel profile, material, heat treat
Primer type
Primer seating (to a much more limited effect than most people think, but it can still cause problems)
Neck tension value
Neck tension consistency
Case fill %
....
....
It's a randomized mess of so many variables anyone that claims to boil it down to single variable solutions is immediately suspect to me. I will tell you the heavy hitters assuming everything else is up to snuff are "component tetris" between the barrel, bullet, and powder, but the other things can all screw you if you do them wrong enough.