Since nobody seems to know, I will answer the question myself. Yes, the hammer extension for the 22LR fits the Varmint Express 17 HMR. My new baby arrived today in time to install the scope and extension and still make it to the range. Not only did the extension fit and function as advertised, more importantly the rifle is a TACK DRIVER!!!!! I shot a 5 shot group that measured 1/4 inch center to center from 25 yds. I eagerly await my next range session, where I will see what I can do from 50 yds. HENRY ROCKS!!!!!!!
