.348 Winchester Brass as an Alternative for the 56-50 Armi Sport Spencer Brass

Over at the CAS City Spencer Forum a couple of gents there have mentioned using .348 Winchester brass as an alternative for to only other source of 56-50 Brass for the Armi Sport Spencer, Starline brass.  After a limited production run, it seems that this brass is again in short supply.  In fairness to the great folks at Starline, 56-50 Armi Sport Spencer Brass is a specialty item and they're running business, not a non-profit. 

By the way - another shameless plug - check out the Spencer Forum at  CAS City.  The folks there are top notch and the forum's moderator, Two Flints, is a true gentleman and Spencer expert.

Here's a table of rim diameters for some popular alternatives to Starline.

Rim Diameter's of various 56-50 brass alternatives as measured by my new digital calipers:

Type	Rim Diameter
8mm Lebel	.630"
56-50 Starline	.630"
50-70 Bell	.655"
.348 Winchester	.610"
32 Gauge Brass	.630"

Although the .348 Winchester rim is about 2/100 smaller than the 56-50 case for the Armi Sport Spencer, I don't anticipate any extraction issues with the Armi Sport Lane extractor. I picked up 50 .348 Winchester cases to try out. Unfortunately my Lyman expander die broke, so I will have to let you all know how they work out in a later post, after I score another  expander die.

Case Dimensions for the Original and Armi Sport (Chiappa) 56-50 Cases

If you have a reproduction Spencer from Armi Sport (Chiappa) in 56-50, you know already that cases for the original Spencer in 56-50 are different than the ones for the Armi Sport.  

Starline makes some fine brass for the Armi Sport, but its been mighty rare for the last year.  A lot of Armi Sport Spencer shooters I know make their own brass from other cartridges, so I thought I'd post diagrams for the original 56-50 and Armi Sport 56-50 for those of you that might want to try forming your own brass from other cartridges.

The original 56-50 has the following dimensions:

The Armi Sport 56-50 has the following dimensions:

As you can see from the diagrams the Armi Sport 56-50 is a touch smaller at the base and rim then the original 56-50.

I have formed brass from 8mm Lebel brass and 32 gauge brass with good results. I'll be posting instructions on how I form Armi Sport 56-50 from both the these cases in a series of future posts so stay tuned!