Mach2 17 cal @ to HM2 17 cal [Archive] - Varmints Den

: Mach2 17 cal @ to HM2 17 cal

04-15-2010, 05:27 PM
I am considering a Mach 2 simply I like the concept of the smaller speed deamon. 80% of the performance at 50% cost. The concern is the chance of the Mach 2 ammo going the way of the DoDo bird. Assuming a bolt action, would it be practical to rechamber to the HM2 round. Is it that much larger to cause feed problems or might get away with a rechamber and a change of clips?

04-15-2010, 07:52 PM
Do you mean 17 HMR to 17 HM2 or 17 Mach 4 to HM2? Or HM2 to one of the others. The title of your post isn't clear, the Mach 2 is the HM2.

The 17 HM2 is based on the 22lr case (actually the CCI Stinger case). The 17 HMR is based on the 22WMR case, it is longer than the HM2. The 17 Mach 4 is a centerfire based on the 221 Fireball.

How easy it is depends on the type of action, you are talking different cartridge lengths and feed and magazine issues may or may not be a problem. As far as the chamber itself is concerned if going from a shorter round to a longer one, it's fairly easy. If you are going shorter you will have to cut off the back of the barrel to get rid of the larger chamber. This also means re-threading and other modifications to the rear of the barrel both inside and out depending on what type of action you are using.


04-15-2010, 09:12 PM
I meant 17 HM2 to 17HMR. I like to statistics on the HM@ but am concerned with the possibility of the ammo going out of production or going up in price due to lower production. I could by 10,000 rounds and be done with it, I suppose. That would be a lifetime plus for me.

04-15-2010, 11:15 PM
Hi again,

Physically rechambering the barrel will be a fairly simple matter. However, action length, magazine design and possibly firing pin position will be bigger concerns than the actual chamber. If you are OK with dropping in rounds one at a time you will probably be OK. If you want to use the magazine you will probably have issues.

If the worst happens and you can't get 17 HM2 ammo you might consider conversion to 22LR. I know it's not as fast but ammo will be available and feeding won't be a problem since the rounds are the same length.

If you have a Ruger rimfire swapping barrels is a simple matter. I have a 96/22 which uses the same barrel as the 10/22. I have a 17HM2 barrel and several hundred rounds but I haven't used it for several years. The Ruger 77/22 uses a slightly different barrel. I jumped on the 17HM2 wagon very early and had high hopes but for my use I get better accuracy and more killing power with the 22LR barrel.

If you haven't already you should check out forumns. The guys there are probably the best source of info online.


04-15-2010, 11:21 PM
HM2 is getting new no-lead ammo. Dead calibers don't get new ammo. Eley's importer has said that the round's sales have increased steadily. But, after saying all this, find what your gun shoots, and stock up. You can find it for less than $4 if you buy big. Then it won't matter. What bolt action are you using?

04-16-2010, 06:54 AM
I havea bag full of rimfires, Marrlin, Remington, CZ, Savage, ect. This is more or les thinking out loud and hankering to feed an addiction. Switch barrel seems liek a way to go rather than getting into tinkering. But, I like tinkering.

charlie sterner
04-16-2010, 07:55 AM
Bought my Contender pistol barrel in 17 Mach 2 and stocked up with a brick of Eley for now. Should last me several years at the rate I get to shoot, but if it were ever to go away, the Contender barrel is a cinch to rechamber to any number of cartridges, even centerfire, since it's just a flip of a lever to convert from rimfire to centerfire.

In addition to the Mach 2 I also have a 17 HMR, 17 AH and 17 FB, but there's some other small centerfire 17's (17 Squirrel, 17 Mink) that caught my eye. Maybe someday I'll do one of those, then won't have to worry about buying rimfire ammo any more.