Size expander plug .002 0ver bullet size. For a .410 dia. bullet use a .412 x .408 expander plug. this will give you .002 clearance to start your bullet and .002 neck tension.
Additional information
Weight
.25 lbs
Dimensions
1 × 1 × 1 in
41 Pistol Expander Sizes
41Cal (P) .412 x .408, 41Cal (P) .413 x .409, 41Cal (P) .414 x .410