Question about case holders

[6bg6ga]

RCBS lists a shell holder for the 45 colt as a number 20 and lists the 44 magnum shell holder as number 18. When checking the base diameter of both they are the same. The rim thickness seems to be within .001-.002 with brass I checked. The 44 mag brass fits in the #20 45 colt shell holder. Lee lists both as the same number so why doesn't RCBS or some others?

[CastingFool]

I was puzzled when I read your post, so I went to check my shellholders. Lee also shows the same shellholder for both calibers. the difference is that the RCBS 18 is sized to conform to the case diameter, which comes out to .455" for the 44 Mag, while the 45 LC measures about .020" larger.

[Harter66]

I sure wish they both or 1 or the other would fit Schofields . Those it appears are a special order ...... oh well.

[6bg6ga]

Actually I have .006 difference between the Starline 45 colt and the #20 holder. The 44 mag as you mentioned comes out about .455 so I'm going to use the #20 45 colt to do both. Any difference in alignment will be taken care of when the shell goes into the die.

[leeggen]

They have to do something to make extra money.
CD

[6bg6ga]

I gave in and purchased a #18 44magnum shell holder just to make sure the case would align properly. I don't like to have any ruined cases because the top got messed up. I will continue to think however that the #20 shell holder will work for both.