I have a Colt New Frontier 6" revolver.



It has both the .22lr, and .22 WMR cylinders.



With the .22 lr cylinder it fires with no problems whatsoever. When I put the .22 WRM cylinder in, problems with ignition occur.



I took the cylinder out and looked at it, and I saw hammer indentations in between the cylinder cartridge holes.



With the cylinder in, the lock up is fine, the rotation of the cylinder is good. Can the timing be so far off, that the hammer is hitting between the cartridge holes?



I've never seen anything like this before.



Any assistance would be appreciated.

congrats on your NF22

im not sure you are aware, but some of the NF were NOT made for 22 Mag.  if you have the box, i should say so or there maybe a model number that has the proper info.  

to answer your question, your NF was most like fanned.  your cylidner could be damaged or the pawl on the gun itself.

your FP could be broke.  if you remove the cylinder and tilt the gun barrel down, the FP should NOT protrude from the recoil shield.  

the timing could be off also,  just reinstall the Mag cylinder and observe the  cylinder while cocking it.

I have a NF that i have had for approx 25 years and had the same problem, it was the firing pin. Have a new one installed or have a good gunsmith repair yours  by " Drawing" it out back to the correct length. I was experiencing the exact symptoms as you, and i have not had a misfire since.