I have 7 or 8 dedicated .22lr magazines for the AR-15/M-16. These are unissued and still in military foil wrappers. Made of a white polymer in the 30 round AR-15 configuration; no more magazine block to use with your .22lr upper. 10 round capacity only. Train with this magazine as you would with a normal 30 rounder.
Now, I will trade the above mags, 1, 2, or all for a decent quantity of once fired or new 45-70 or 6.5x55 Swede brass cases. Tell me what you have and we can work out the details.
My e-mail is KCSC22@aol.com