I came across some of this and it's longer than st 22LR but shorter than a 22 Mag. I have a S&W M48 and was wondering if this could be shot safely in my revolver. I have never seen this ammo before

I have an old H&R 22 Special 22 WRF revolver.You can fire 22WRF in a 22 magnum,but you can't fire a 22 magnum in a 22 WRF.Recent factory ammo was produced on limited runs by Winchester and CCI.Winchester stuff was supposed to be loaded a little lighter for revolvers and rifles and the CCI loaded a little hotter and was recommended for rifles.The cowboy shooter's sparked a demand for the ammo,but it will probably be a good while before any new production will occur.I haven't bought any in about twelve years and at that time I paid about $7.50 for a box of fifty.I'm sure it would go for much more than that at the present time.

Would caution you on use of WRF ammo in a WMR. SAAMI spec bullet diameter for the WRF is .228”

The 22 Winchester Magnum was designed by lengthening the 22 WRF with its .224 '' diameter bullet so that it couldn't be used in the old 22 Spl or 22 WRF rifles. Using the 22WRF rounds in a 22Win rimfire magnum has the same problems as using 38Spl in 357 Mag chambers. Carbon and lead buildup. Somebody has found an error of bullet diameters. That 22WRF bullet runs about 1400fps and kills slightly better the 22 lr bullets but is a pretty good bullet for edible game with a 22 Wincester Magnum rifle.

my ruger single six 22wmr replacement cylinder by borchardt (http://rugercyl.com/ruger-cylinders/) works great except that 22wrf rounds are a tad too wide to fit. i will try 22wrf rounds in a heritage roughrider and ruger lcr 22wmr later...