Home Forums Hunting & Shooting Rimfires .17Mach2 split cases

Buddy called and wanted to do some squirrel hunting, so I thought I'd sight in the CZ 452 .17Mach2.

Haven't shot the gun in years (Like 8 or so), so I thought I'd get it on paper with some Hornady ammo I had, then get it tuned in with the Eley ammo.

50 yard Target...



As you can see, the Hornady was all over the place. I picked a spot just above, and to the left of the Hornady "Group" (using that term very loosely), and shot a 5 shot group with the Eley.

Now I remember that the gun shot the Eley a little better than other ammo, but yikes, the Hornady was terrible.

When I was back at the bench, I saw one of the fired Hornady cases laying there.
Here I lined up the Hornady, with the spent Eley cases...
I ended up searching, and finding all 10 Hornady cases, and all 10 were split.



Closer look...



I'm wondering if the brass on the Hornady cases hardened over the 9 or 10 years that I've had it.
You can see on the Hornady box it's stamped "First Production Run".
Maybe that's the problem?

Not the end of the world, I have 3 bricks of the Eley, and a brick of CCI.
The 2 boxes of Hornadys just became dust collectors I guess...

The Eley ammo gives you the answer you are looking for , the Hornady ammo must have a problem

I had a batch of eley ammo split exactly like that a few years ago. It shot terribly as well.
Another lot of eley didn't split and shot well.

The original Hornady ammo did that, so those who bulk ammo'd up day one are still having that occur. At one time they had an exchange program where you could get it replaced, if you search around they have listed the bad lot numbers somewhere.

You can email Hornady and they'll likely replace them.

Cheers,
Spot

Just found this...

Warning About 17HM2 Brass Cracks and Ruptures:
Cracks may be visible in fired 17HM2 cases. This is not unique to 10/22 conversions but also appears in 17HM2 bolt guns, etc. An unnamed source at Hornady said they were aware of this and had done tests that showed it did not effect accuracy or performance. Apparently the cases cannot be annealed during the manufacturing process. Always wear safety glasses and hearing protection.


http://www.eabco.com/ruger1022warnings.htm


"An unnamed source at Hornady said they were aware of this and had done tests that showed it did not effect accuracy or performance."

There is, as there always has been, a lot of 17HM2 talk over on RFC on about any topic that you can think of.

My 17HM2s shoot better groups with Eley and Eley-made Remington ammo that with any of the CCI/Hornady that I've yet to shoot. I recently bought a couple thousand rounds of Hornady 17HM2 in lot #s G28X34 and H09x39, but I haven't shot any of it yet.

I had a 17hm2 that would occasionally have split case with ELEY ammo. I found that the all it needed was a good cleaning and the split cases went away. The 17hm2 shoots much dirtier than a 22lr and requires cleaning much more often. May not work for you but would give it a try.

My Kimber 1911 conversion would bulge cases just ahead of the rim because it would fire while slightly out of battery, which happened if it got dirty. Never had a split.

BGunn: Yikes!
I have three different heavy barrel Varmint Rifles in caliber 17 Mach2 and have shot munitions by Remington, C.C.I., Eley, Hornady and Browning (IIRC on the Browning - it was only made for a short time).
And have as yet to have a split neck (let alone a split case!) in any Rifle with any ammunition!
And... I got on the 17 Mach2 bandwagon right from the get go.
My Rifles are by Anschutz, Kimber and N.E.F.
Let me ask this did you fire that Hornady ammo in your Rifle 8 years ago?
Hold into the wind
VarmintGuy

When I first bought the gun in 2005 or '06, I bought Remmington, Eley, and Hornady ammo.
To be honest, I didn't look at the cases after I shot them. After shooting about 10 of each type, it was very obvious that the Eley was what the rifle really liked, and went out and bought 3 bricks of it. The Hornady was just left over from that original sighting in of the rifle.

As I stated, Hornady has known of the situation, and seems to believe that it's not a problem at all...
Me.... I won't be shooting any more Hornady ammo in my gun.

I really like the .17Mach2 too. I have a Anschutz 1422 Meister grade 22LR, and this CZ runs neck and neck with it on paper at 50 yards.