Larsen E. Pettifogger, SASS #32933

Again, no brand has the maximum size rim by design.  It is a matter of tolerance stacking and tool wear.  I have several .44-40 guns and ammo from one won't necessarily work in another depending on the bullet OD and case brand used.  I have standardized on the original bullet size of .427.  This fits all of my current guns.  I have .44-40s that vary from .423 to .432.  In the old days SAAMI did not exist so the dimensions for the chambers and cases were/are not uniform.  I have had the worse luck with Remington and CBC.  Both of those frequently have rims that won't fit in some of my guns or stick in the shell plates on my reloading presses.  So, I now only use Winchester or Starline brass.  They have the thinnest case necks and seem relatively consistent for rim size.  As an example, suppose the reamer your smith used was towards the maximum.  That would allow the cases to move outward from the centerline and give the rims a tiny bit more space.  A tighter chamber with wider rims and they would be a no go.

 As I noted in my response on the thread SOME people have had .44-40s custom made.  I said Ruger says they cannot be produced on a mass production basis.  The reason is the cylinder base circle was changed from the Vaquero to the New Vaquero to accomodate the smaller frame.  All manufacturing has tolerances.  Ruger has to be able to ensure that a maximum size case will fit in a minimum size chamber, etc.  The max size .44-40 rims won't the min size rim recess in the ratchet so Ruger won't (at least so far) make them.  Hard as it is to believe Ruger actually knows how to make guns.  You had yours custom made and can control the type of brass used in the gun.  Joe Blow buys a gun and any ammo he can find.  If it don't fit Ruger will get a nasty letter.  What I wish Ruger would do is make a dual cyllinder .32-20/.32 Mag in the New Vaquero.