SWFA appears to have Fiocchi 1575rd ammo boxes
Fiocchi SD Ammunition .22LR 40gr PLRN Plano Can of 1575 | SWFA
Kind of spendy at $129 but I hear comparable to minimags. Shipping prices are also harsh.
1 box = $150 w/ shipping $0.095/rd
2 boxes = $260 w/ shipping for the curious $0.0825/rd