I won't be using these.... ever again

[Dieseldrvr]

Went to the range today. Tried two boxes of Winchester Super X that a friend gave me. First off, after shooting a box of CCI, I was showing off the
.17s accuracy. Had a couple very good groups at 80yds, then stood up a bunch of 12 gauge shells at 80 and picked em all off, 15 for 15. I love my 17.

Now the problem. I loaded a mag of the Winchester. My half inch groups were now a best of 1 3/4". I couldn't hit the new shells we set up either.
WTF? About 10 rounds into the box, I cycled the bolt and the next round would'nt load. I looked down to find a round still in the chamber. WTF?
I had to pry it out. When I did, I found that the casing had split.

I went through all my brass on the ground. I found all 20 spent Winchester casings. 7 of them were split.

I stopped and completely cleand the gun, checked everything I could think of. Found nothing wrong with my gun.

I ran two more boxes through it (not Winchester) and I was back to shooting the way it always does. Not one bad casing out of the next 100.

Any input?? I know I wont be using this ammo again.

[FredoSD]

WOW, not that it would do any good but I'd send those casings to Winchester and ask them WTF?

[Dieseldrvr]

yep

I'm normaly a cranky complaining consumer... but, this time I will write a letter.

[Izzy43]

Winchester .17HMR is known for that issue. Lots of complaints over on rimfirecentral.com about that ammo. I've gone thru several thousand rounds of Hornady 17g ammo and never saw a spilt case. Rumor has it that Hornady makes all the .17HMR ammo and packages it for different companies but with the different companies specs on the powder loads. Emphasis on rumor.

[Yoteman]

Please notify Win.