Thread: Primer Leakage

or different brass

CCI400 primers are too soft for the 17 Hornet. Use a harder primer. Or you may have a headspace problem; oversizing the brass which allows the primer to back out and leak.

I've got lots of experience loading for the .17 hornet, I had two, Both CZ sold one to GWH on here,
Get rid of the little gun its too prone to pressure problems, My results were similar, blown primers at starting loads.
I recommend, that you get a lb of CFE blackout, or N120, these are the stand out powders from my .17 hornet experience, H4198,(ADI 2207) and 4227 (2205) will be a little slow, but also less pressure.
Hornardy and resized .22 PPU hornet brass, are the same capacity, Winchester and Remington brass will have at least 10% more Capacity, this is were we run into pressure problems with .17 hornet,

I use a load of CFE blackout, 12.5gr, CCI 400 or WSR primers, Hornardy or PPU Brass, with a 20gr. 3650fps in a 20" CZ.
The 25gr V-max or Hollow point, at 3100-3200 fps are very effective, and there is no doubting a hit, the whump.
look after your brass, I neck size most of the time, Anneal when it gets hard, 5-8 firings, I am up over 15 firings now on sum Hornardy.

here's a couple previous threads for your info.
Saubier is the best place for further info, have fun and be very careful with little gun, its only 1/2 a grain between bang and boom.
https://www.nzhuntingandshooting.co....ght=.17+hornet
https://www.nzhuntingandshooting.co....ght=.17+hornet

Oh forgot to Add, early Hornardy factory loads, had dished heads, if yours are ,chuck them out, and a firm squeeze on the hand priming tool, stop once you fell resistance increase,
It may be worth the $20 or so, to get a primer pocket reamer, to get them all round and sized, sum .17 hornet, Hornardy factory ammo I had wasn't very good.

Well Charliehorse,
You seem to have plenty to work through now. A few more things I neglected to mention but will now add to the heap.
First, hand primer tools can seat the primers not quite straight in the case. After the initial seating I have always rotated the case 180 degrees in the case and applied a little more pressure. Often you will feel the primer seat a smidgen (to use a technical term) further. This will take some dexterity to stop the next primer feeding but is easy to master.
Second, if you are full length sizing only size enough to ensure that the case chambers freely. Your die may not contact the shell holder but this is fine.
And finally, to climb aboard one of my favourite hobby horses, if you can chronograph your loads this will give you a good understanding of pressure. If your velocities are close to the Hodgdon data (after adjusting for barrel length) then your pressures will be also.
You have been blessed with an interesting cartridge. Enjoy it.
Grandpamac.

Thanks, all good stuff. Back to the drawing board then. Hopefully the forum Chrony turns up soon so I can do some testing