Modifying 50-70 Government Cases

[paledun]

I am in the process of modifying 50-70 Government cases to provide 56-50 caliber cases to reload for an original Spencer Carbine.  While Starline makes 56-50 brass, their rim diameter is not wide enough to provide reliable ejection.  Since the rim of the 50-70 is just right, many Spencer shooters are using them.  And, most Spencer shooter are reloader, as I am, but not fully experienced with a full range of reloading experience.  That is why I thought to bring my questions to this forum.  No concerns with cutting the longer case and trimming to proper length.  Been doing case trimming for years.  But, I have never had to address case wall thickness in the past.  This is a concern with the wall thickness of the trimmed 50-70 in the chamber of my carbine.  I have an additional thickness of .006 inches in total diameter due to the thicker wall thickness when compared to original Spencer rim-fire cases.  Not much but chambering and extraction is difficult.  My question is the best next step, outside wall trimmer or a neck reamer?  I have no lathe to secure the case so I expect to use a Forster or Pacific trimmer to hold the case.  With that simple set-up, outside or inside?  Cost, outside or inside?  Since a 50-70 case is over $1.00, I want real consistency, outside or inside?  Thanks, in advance, for your best advice.  Paledun

[Fox Creek Kid]

You'll get better answers here:

http://www.n-ssa.org/vbforum/forumdisplay.php/8-Civil-War-Small-Arms

[JimBob]

Inside neck ream,you want to maintain exterior uniformity and taper.They make neck ream dies with a reamer but they are expensive.

http://ads.midwayusa.com/product/836935/rcbs-neck-reamer-56-50-spencer

http://www.midwayusa.com/product/120662/rcbs-neck-reamer-die-56-50-spencer