I'm shooting with three different rifles. A CZ455, Ruger Precision Rimfire, and the Ruger American. The first two are sporting Green Mountain 17 cal. barrels chambered and fitted by my local gunsmith for the 17hm2. The third rifle is the one I just picked up from Whittaker Guns in 17hm2.

I've found the CCI and Hornady 17gr V-max's to be very close with the Hornady sometimes edging out the CCI as far as accuracy. Best groups were just under a dime size. I tried the TNT ammo but found it to be less than accurate for my purposes. All groups were at 50 yards. Torque settings on the action screws played a role on how well the guns shoot. Each gun is different as far as torque settings as one might guess.

 

I'm shooting with three different rifles. A CZ455, Ruger Precision Rimfire, and the Ruger American. The first two are sporting Green Mountain 17 cal. barrels chambered and fitted by my local gunsmith for the 17hm2. The third rifle is the one I just picked up from Whittaker Guns in 17hm2.

I've found the CCI and Hornady 17gr V-max's to be very close with the Hornady sometimes edging out the CCI as far as accuracy. Best groups were just under a dime size. I tried the TNT ammo but found it to be less than accurate for my purposes. All groups were at 50 yards. Torque settings on the action screws played a role on how well the guns shoot. Each gun is different as far as torque settings as one might guess.

I agree with all this. Though I've found the CCI to be slightly better than the Hornady. All my guns can shoot in the .200s and .300s until the inevitable flyer of a fourth or fifth round that blows the group to .600, .700, or worse. All at 50 yards. Such is the way it is with the poor ammo. At 25 they're stupid accurate.

I'm shooting an Annie 1502, VQ Summit, CZ 457 w/ Lija barrel, and several 10/22 conversions. The Summit is the least accurate, as that carbon barrel gets hot and groups sour, but it's the most fun to shoot. The CZ and Annie are about the same accuracy wise, but the small lighter CZ handles better. The 10/22s are just fun, especially the Charger.

 

I'm watching this thread closely. I've never even seen a Mach 2 round. I'm still on the fence about the Lilja barrel for my 457 Scout.

 

Here's a couple pics. Hornady hm2 round.

I am shooting hm2. Might do a video and show some 50 yard groups. Might show something else too.

 

17gr ammo CCI seems more accurate of new ammo
15.5 is the hornady.

Went shooting again today and the 17hm2 is my favorite round but the wind is hard on it (worse than my 22’s or 17hmr).

Accuracy wasn’t as good today (cleaned the barrel and then is was blowing like a bugger).

 

I just wish they'd make a 17 hm2 like aquila does, without the plastic tip, for hunting.

 

I have 3 17hm2 rifles and I have tried both Hornady and CCI in all. My Remington 581 with an Anschutz 1502 barrel likes Hornady, TC R55 likes CCI and my Summit with an ER Shaw barrel likes Hornady. You wouldn't think the ammo would be different but I do see a change from one brand to the other. The 15.5 grain ammo is terrible in all.

 

I shoot an Anschutz 1502. I've found no consistently discernible difference between the various Mach2 ammos. My rifle did like the Federal slightly better but you can't find it any more. Sold my Eley because it was selling for a good price and didn't shoot any better than my cheaper stuff. Did try the newest CCI iteration and had a serious problem with it; half the shots winging completely off paper.. I reported it to CCI, but they blew me off and offered nothing by way of compensation. It seems my rifle handles all of them reasonably well.

 

This past summer I did some extensive testing of .17HM2 brands/lots with my Kimber K17 ProVarmint 20 inch barrel, at 50 and 100 yards. I tested 2 lots of Eley, 4 lots of Hornady, and 5 lots of CCI including CCI-VNT. The results of group size measurements showed that the lot/batch number had more effect on group size than brand. Usually, a flier would open up the group size, some worse than others. Thinking about this further, I went back to the sorting techniques published by Steve Boelter of ANA. He proposed that .17 HM2 accuracy could be improved by measuring bullet seating depth from ogive to rim base. I developed a measuring tool similar to his. I modified my rimfire gauge to measure the ogive length from the base of the rim, and sorted 11 lots of Eley, Hornady, and CCI (.17M2) into consistent groups.
I found that for my Kimber K17 ProVarmint there was a certain ogive length that gave consistently smaller groups with no fliers. Within any given lot the ogive length could vary by as much as .016" due to seating depth. This is considerable and points to the lack of quality control in these rounds. Hence no "match grade" ammo is available for .17M2 (and probably for .17HMR) simply due to variations in bullet seating depth, as well as other factors. One cannot measure the OAL with any meaningful results because the little plastic V-tip dimensions can vary by .010".
In my testing, the best sorted ammo lots made 5-shot groups at 50 yards as small as .377" while the same lot with different ogive lengths shot as poorly as 1.301".
For my rifle, the best groups were obtained with an ogive length of 0.983" regardless of brand. The ogive lengths seemed to vary by lot/batch number rather than brand. This is not surprising since all of today's .17HM2 is manufactured by CCI. I also noted that my 2 old lots of Eley had the lowest variation in bullet seating depth, which probably accounts for their reputation for accuracy.

I don't claim that sorting can make match grade ammo, but it did eliminate the fliers, at least for my rifle. Other rifle chambers may not be as sensitive as mine to variations in ogive length. (bullet seating depth).

It would be nice if CCI would step up to improve quality control, but I doubt that they would view that as cost effective.

I know others have stated that sorting rimfire ammo is a waste of time, and I have found that to be true of .22LR. However the .17M2 and .17HMR have copper jacketed bullets that seem to behave similar to centerfire rounds with respect to chamber pressure.

Other notes from this testing: I found that accuracy for my rifle dropped off after about 100 rounds and required barrel cleaning. I also tested some lots at 200 yards with disappointing results as most bullets key-holed in the target, probably due to the transition to sub-sonic velocity at about 180 yards. Several lots of Hornady showed higher velocity and did not key-hole. I concluded that the .17HM2 is only useful out to about 150 yards in my rifle. I found that these little plastic tipped bullets can act more like centerfire rounds than we are accustomed to with .22LR rounds.

 

This past summer I did some extensive testing of .17HM2 brands/lots with my Kimber K17 ProVarmint 20 inch barrel, at 50 and 100 yards. I tested 2 lots of Eley, 4 lots of Hornady, and 5 lots of CCI including CCI-VNT. The results of group size measurements showed that the lot/batch number had more effect on group size than brand. Usually, a flier would open up the group size, some worse than others. Thinking about this further, I went back to the sorting techniques published by Steve Boelter of ANA. He proposed that .17 HM2 accuracy could be improved by measuring bullet seating depth from ogive to rim base. I developed a measuring tool similar to his. I modified my rimfire gauge to measure the ogive length from the base of the rim, and sorted 11 lots of Eley, Hornady, and CCI (.17M2) into consistent groups.
I found that for my Kimber K17 ProVarmint there was a certain ogive length that gave consistently smaller groups with no fliers. Within any given lot the ogive length could vary by as much as .016" due to seating depth. This is considerable and points to the lack of quality control in these rounds. Hence no "match grade" ammo is available for .17M2 (and probably for .17HMR) simply due to variations in bullet seating depth, as well as other factors. One cannot measure the OAL with any meaningful results because the little plastic V-tip dimensions can vary by .010".
In my testing, the best sorted ammo lots made 5-shot groups at 50 yards as small as .377" while the same lot with different ogive lengths shot as poorly as 1.301".
For my rifle, the best groups were obtained with an ogive length of 0.983" regardless of brand. The ogive lengths seemed to vary by lot/batch number rather than brand. This is not surprising since all of today's .17HM2 is manufactured by CCI. I also noted that my 2 old lots of Eley had the lowest variation in bullet seating depth, which probably accounts for their reputation for accuracy.

I don't claim that sorting can make match grade ammo, but it did eliminate the fliers, at least for my rifle. Other rifle chambers may not be as sensitive as mine to variations in ogive length. (bullet seating depth).

joet333:

That is very interesting. You dont happen to have an extra one of those "measuring tools" laying around do you ? I would like to give it a try.

 

It's pretty easy if you already have a rim thickness gauge. I'll try to post some photos of the setup.

 

joet333:

I do not have a rim thickness gauge…. I am pretty humble or modest in some equipment..... But, the thought of creating a measurement for better accuracy really hits my trigger so to speak.....

I do have a stash of Eley but I would, like you, like to sort the various ammo makes into performance groups

 

I just got my CZ 455 with a whistle pig barrel put together last weekend. So far I've shot CCI 17 gr Vmax and Hornady 17 gr Vmax. The hornady so far is a bit better at 50 yards. It's been so windy I haven't tried out to 100 yds. It's a fun little round. I also have a box of CCI VNT which I haven't tried. No one local carries it but I kind of expected that.

 

I have found that the accuracy of CCI and Hornady can vary quite a bit from lot to lot.

I don't understand why CCI can't make 17HM2 ammo that is as consistently accurate as the old Eley and Eley-made Remington, maybe it is rocket science after all.

The 15.5 NTX that I bought because it was cheap hasn't shot good groups in any of the 4 rifles that I've tried it in.

 

Attached are some photos of my set-up to measure the bullet seating depth from ogive to rim base. Any rimfire gauge can be modified to do this using a brass tube
(model airplane tubing) having a 0.155" ID or #22 drill bit. The idea is to support the cartridge at the ogive and measure the length from the zero reference. Other style rim gauges can be likewise modified. An empty .223 Rem case makes a great rim thickness gauge using a dial caliper. A quick easy way to do this would be to fill the .223 case to the neck with epoxy, let it cure, center the case and drill it with a 0.155" inch drill to a depth that would allow about 1/8" of the .17HM2 cartridge stand proud.

 

joet333:

Thanks for the pics. I think I will see if I can fabricate one. If not I'll let you know.