If your Iver Johnson is marked for the .22 WMR.then yes,if it is not then do not attempt to load or shoot .22magnum ammo in your rifle.
About $750, depending on condition.
50-150
200+ ft. lbs at the muzzle
You will have to call Henry to find out.
.17 is the caliber, HMR means "Hornady Magnum Rimfire".
I think the .17HMR would be a better choice all around, I have both and the 17HMR is better by far. The .22 bullet travels about 900'-1300' FPS and the .17HMR travels at 2200'- 2500 FEET PER SECOND.
.17 is the caliber, HMR means "Hornady Magnum Rimfire".
No.
rim fire as a 22cal.
NO NO NO! Only shoot what the rifle is chambered for and so marked.
No