Recently bought a Ruger #1 in 405 Win. , just returned from the range after firing a box of factory loads and 40 handloads.
All I can say is I'm very impressed and I don't impress easy!
Factory ammo will easily shoot into 1 1/4" 3 shot groups and most reloads did very close to the same. Max velocities reached 2350fps with 3031/ 300 Horn. FP with good accuracy.
I would appreciate hearing from any other Ruger #1 405 win. owners as to what shot the best in their rifles.