Something close may work. I have .22-15-60 brass and a line on a rifle to shoot it. Trying to keep ahead of the curve. Also looking for dies.

The Ideal Handbook #15 states:
    " .228 is the standard diameter of bullets for rifles using the following cartridges:  .22-10-45; .22 Extra Long C.F.; .22-13-45 W.; 22-20 Hornet, etc. "

Some of the old Winchester moulds were cut to cast to that larger groove diameter used for the early 22 CF calibers, and I obtained a WRA mould for the 22 WCF (which duplicates the 45 grain Ideal #228151 bullet) that does cast to 0.228".

I trust that you've already looked at your Stevens #50 catalog which shows the 22-15-60 could be loaded using the range of bullets weighing from 32 grains and upward.
Stevens own recommendations of using their various listed bullets "tempered" at "1 to 75", "1 to 60" and "1 to 30" , with the heavier bullets using the softer mixes and the lighter weight using the harder mix, provide interesting food for thought for experimentation.

You might also look for bullet moulds that were cut for the 22 Savage High Power, which also used the larger 22 CF groove size specifications.

Or maybe you could get J Louis to cut you a mould?

If you don't have the gun yet, you might want to wait and slug the bore to determine for sure if .226" works or not?

I have some that you might use.   Check your hotmail.   

Phil

Been trying to contact Bullshop from the previous .22WCF thread. He has them on his website but I haven't been able to figure out how to contact the shop or order them from him. The .22WCF bullets should work in the .22-15-60. Bullets are lighter than the orginal factory loading but the diamater is right and they should work to get it shooting again.