Charles, two separate Cylinders have always been required due to significant case size difference which would be unsafe attempting to fire 22LR from a 22Mag Cylinder. 22Mag will not fit in a 22LR Cylinder. It is the reason all dual caliber combo pistols come with (2) Cylinders : budsgunshop.com/product_info.php/products_id/87939/heritage+manufacturing+srr22mbs4+rough+rider+6rd+22lr%2f22mag+475%22+steel+frame

The two cylinders are not interchangeable. You must use the proper cylinder to shoot only the cartridge it was designed for..

2

they require different cylinders as the 22WMR has a fatter case and will not fit in a 22lr cylinder. If you fire a 22lr in a 22WMR cylinder the case could rupture (to loose and not supported) causing a unsafe condition

Yes seperate cylinders are required, as the 22Lr and 22Wm are different size and pressure cartridges, not all 22 Lr have a 22Wm cylinder available and not all 22Wm have an available 22lr cylinder l, but some revolvers come with both.