I have an 044-1/2 in .22-15-60 SS.

Read a article from the developer of the 22-15-60 Stevens
when he approached Stevens A & T in 1897 .

This is one scarce cartridge , apparently very flat shooting 

Have you shot either of your rifles ? 

I have one box (20) of ammo and trying to make a deal
for a ''Favorite'' (special factory order).
... skwerl

I’ve shot mine with a few original cases and a fair number of Rocky Mtn Cartridge Co lathe-turned cases.

Used Ideal 22636, also the HP version, and the 45-gr Winchester bullet (same diameter) for the .22 WCF.  So far, only hunting-grade accuracy; not what I can get from the WCF loadings.  Beware trying to soup up the velocity; easy to loosen primers in those expensive cases.  Even moderate loadings might be marginal in a Favorite.  Is it the Ladies’ Model?

The bore on my 044-1/2 is a little frosty, but the barrel sights might be more a limiting factor with my bleary aged eyes.  I ought to put a tang sight on it and see if that helps.

It’s an interesting curio from the time when the “outer limits” of black powder cartridges were being explored. I’ve basically had the same results from the .25-25 Stevens, and the .40-90 Sharps Straight.  Ho-hum plinking accuracy, and any attempts to speed them up beyond what can be gotten from .25-20/21 and .40-65/70 cases is not cost-effective, if you consider case life into the equation.

But there’s nothing so boring as ammunition you can buy in a store.  The madder the caliber, the more I’m intrigued.

I’ve got a 44 with a decent bore and some lathe turned brass. Put together a few black powder loads. Reasonable plinking accuracy. Rare chambering and hard to find.

20 cases machined from solid would be half that, and you wouldn't be upsetting cartridge collectors by shooting old stock ammo.