bigpete wrote:So in that case I should be able to rub it of really easily...
Regardless,if you actually read the articles, the speeds are not exceeding 1600fps anyway.
And none of this conjecture is actually answering my original question ; who owns or has used one ?
Yep, 100fps seems a poor result for the amount of money spent for the .20-cal, and just 200fps for the .17 seems even worse.
Never even heard of it, at least not that I recall. I'd happily build one just for giggles but I wouldn't expect it to offer any advantage over a .22LR.
Brownells list a .172" 9"-twist barrel blank for A$240, although out of stock currently.
A .22LR chamber reamer and a bit of finessing the throat seems like a fairly simple job.
If you could find a cheap .17Mach2 rifle all you'd have to do is put a .22LR reamer in it and taper the throat.
Trying the same trick with .22WMR in a .17HMR barrel might prove more interesting.