Split case

A

Abndoc

New member
I went to the range today with my Dad. He was shooting his near new Savage 93 in .17 cal with, I believe Hornady 17 gr V-Max cartridges. This rifle was on its second box of ammo since new.

Anyway, I noticed that about every 3rd round had a failure to extract. After getting it out of the chamber, my Dad looks at it and says "Just as I thought."
Seems this had happened to him before.

The cartridge had a small split in the neck down into the shoulder. The shoulder seemed to be slightly streched and rounded. This seems to me to indicate that the chamber is mis-reamed or that the headspace is not right. I am not a gunsmith, but even to me this doesn't seem right. Should we send this rifle back to Savage? Or could it be an ammo problem?
 
common occurance

This appears to be a caliber specific problem. A good many folks have had the same problems with the 17 HMR's, not so sure about the lower pressure 17HM2 though. Most haven't been bad enough to have the manufacturer replace or rechamber any barrels since no one reloads rimfires, but if it gets to be a problem, then yes, send it back and have them check it out. Make sure to send back several of the empty cases so they can see exactly what the chamber is doing to the case.

I would simply advise you to make sure to clean the chamber well and then make sure the extractor has a good hook on it and that it is positive in it's engagement angle to the case. I haven't heard of any curealls so far with this round, but most of the semiautos have had the problems and not the bolt actions, although some have had troubles with it as well. If it smooths out, all the better, but most that I have seen will ruin the cases now and then but have not seen a catastrophic failure so far with them myself. Good luck with it.
 
The description of the shoulder changing shape bothers me. It can be expected to become a bit bigger, but the shoulder rounding should not occur. I took a look at the Reamer dimensions on Clymer's web site, and there is no shoulder rounding indicated. I also noticed they make both a standard and a match reamer for .17 HMR. The match reamer has 3.5 mils smaller base diameter, 2.5 mils smaller shoulder diameter, and it is 0.5 mils smaller in the case neck. Rather than shorten the freebore as most match reamers do, they increased the throat angle from 1.5 degrees to 2.5 degrees to get the bullet started on the rifling sooner. I don't know why they chose that alternative? Getting a chamber cut with this match reamer might reduce the case expansion just enough to achieve case survival.


Abndoc,

Any chance you could post a picture of a fresh cartridge adjacent to one of your fired cases that did not split and one that did?

One other thought: Next time you go to the range, place all rounds in the chamber individually using your fingers so you can put the headstamp lettering in the same orientation for each shot. This way you can see whether the split occurs at the same place in the chamber each time? If so, it points to a chamber defect; being slightly oval, for example. This might explain the shoulder rounding if it appears more on one axis than the other?

Nick
 
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