Dangerous and Expensive Problem with 17 HH

[accurate shooter]

I had an expensive and possibly dangerous problem with the neck diameter on 17 HH brass. I had a reamer built after measuring 25 rounds of factory loaded brass for two dimensions: Loaded round neck diameter, and headspace. The Loaded Round Neck Diameter only varied .0002" and the headspace only varied .0009". That is, of course, remarkably consistent. The reamer was specked to this brass and had a .196" neck diameter to fit a loaded round neck diameter of .193". The next box of ammo I bought had a loaded round neck diameter of .198!! If I had fired this ammo in my new rifle, I would have had a neck crush fit of - .002" Hornady, this is dangerous, and my newly chambered rifle is useless. I am speechless that a great company such as yours would create such a dangerous condition in your ammo!!

 

[drover]

Did you contact Hornady? And if so what was their response?

drover

 

[jepp2]

Hornady, this is dangerous, and my newly chambered rifle is useless.

You specified the neck diameter, and now it is Hornady's fault? Sound like your no turn neck, just became a turn to neck. That is why they make neck turning equipment.

 

[457ciSBC]

You specified the neck diameter, and now it is Hornady's fault? Sound like your no turn neck, just became a turn to neck. That is why they make neck turning equipment.

Well in his defense the SAAMI chamber neck is .1955 to .195 taper. That just seems to be rather tight for a .17 factory neck, even with thin brass. If the factory ammo has a .198 neck, that is certainly some degree of liability I would think.

 

[B23]

The neck thickness for factory 17 Hornady Hornet brass has a good amount of variance in it.

I have multiple different lot #'s of 17 Hornady Hornet brass and I've measured some Federal American Eagle 17 HH brass which is just relabeled Hornady 17HH ammo and the neck thickness varied from .009 - .012

Neck turning certainly isn't hard work but I find it about as fun as having my toenails pulled out with a set of rusty pliers so instead I use a Redding bushing die and keep my brass sorted by its neck thickness to control the desired neck tension.

Accurate Shooter, I'd say you have one of two options. 1) Have your GS go back in and open up the neck diameter. 2) Neck turn all your brass to fit your gun.

As much as I hate neck turning, if you don't keep your brass sorted by neck thickness and you aren't using a bushing die, option #2 is your best choice particularly with regard to accuracy.

 

[JSH]

17HH, weigh your brass. I sorted mine out by weight, definitely a difference.

 

[B23]

17HH, weigh your brass. I sorted mine out by weight, definitely a difference.

I've done this and you are correct there is definitely a decent size variance in the weight of the brass, BUT, I went one step further and actually measured the internal case volume, with water, for many of these 17 HH cases of varying weights and the internal volume was very close. All were 14.7 +/- .1 either way.

It's relatively common in some brass to have a fairly significant variance in overall case weight from one piece to the next yet still have a relatively consistent internal case capacity. Kind of why weighing cases doesn't really do much for you, it's consistent case capacity that matters.

 

[JSH]

There was a definite capacity difference between the two. I was using 4198, load was ok in one case and completely run over on the next.
6 grains difference per case weight is pretty substantial difference on such a small case.

 

[B23]

I looked through my notes and of those that I weighed the lightest was 49gr and heaviest was 53.3gr but both held 14.7gr H2O. Interestingly enough the case that weighed 49gr also had the thinnest neck thickness at 9 thou and the 53.3gr case had a neck thickness of nearly 12 thou.

 

[JSH]

B23, any thoughts on a collet die?
I have neglected my 17HH for a while. This thread reminded me why. (Sorry to the OP for the derail)
Some one gave me all the info on using a 17Remington collet die to make one for the 17HH and I was thinking it would work for the 17FB as well. I went and looked and have three 17R collet dies, I know one came in a box of stuff from an auction, the other I am sure I bought for the 17HH.
Danged if I know what I did with the info.......

 

[searcher]

I had an expensive and possibly dangerous problem with the neck diameter on 17 HH brass. I had a reamer built after measuring 25 rounds of factory loaded brass for two dimensions: Loaded round neck diameter, and headspace. The Loaded Round Neck Diameter only varied .0002" and the headspace only varied .0009". That is, of course, remarkably consistent. The reamer was specked to this brass and had a .196" neck diameter to fit a loaded round neck diameter of .193". The next box of ammo I bought had a loaded round neck diameter of .198!! If I had fired this ammo in my new rifle, I would have had a neck crush fit of - .002" Hornady, this is dangerous, and my newly chambered rifle is useless. I am speechless that a great company such as yours would create such a dangerous condition in your ammo!!

Actually - that is normal from what I have seen with most any ammo manufacturers. As long as the ammo is within specs of SAAMI, all is good. When you go minimum spec - you have rolled the dice as to whether your factory ammo will fit or be safe. I like going tight on shoulder "headspace", as I did when I re-barrelled my .17HH, though if it is a gun I'm shooting factory ammo out of - no way will I reduce the neck.

 

[Ajohnse]

I have a .17 Cooper Mach 4 and it’s been my experience that the necks start to grow a bit. If you want to shoot the .17 center fires I think you better get used to turning necks.

 

[dedogs]

If you want to shoot the .17 center fires I think you better get used to turning necks.

That has not been my experience. I get paid to kill varmints. I have three different 17 caliber rifles. One has 20+ loadings on the brass. The other two are north of 10 loadings. I shoulder bump my brass therefore it is full-length resized each time. Anneal every 4th loading. I don't "hot-rod" any of them as there is no need. I have yet to turn a neck on any of these cases. YMMV. dedogs

 

[B23]

I have a .17 Cooper Mach 4 and it’s been my experience that the necks start to grow a bit. If you want to shoot the .17 center fires I think you better get used to turning necks.

How does neck growth and neck thickness correlate?