17 hornet

[17tbs]

Originally Posted by georgeld

Bob:

That NEF I had rechambered for the VR
was done with a reamer of ;192".

at least half the cases I fired in it split the shoulders.
Ended up sending it to Paul and he opened it to .195".

No problem since.

Neck was so tight it locked the case up solid and had no where
to expand.

Hope you don't find that with your new gun.

George, I just checked my reamer print and reamer, it was set to .1980" so a .192" or even a .195" seems like a pure virgin by comparison. My loaded brass though is .1973 with the sized brass coming in at .197" I have had no split necks from the tight neck area. I did some calculations on the brass and way back calculated that there would be 0.000325" spring back per side for .172 caliber rifles with .198" chamber necks and a 0.0005" clearance. I pulled the expansion and spring back calculation / data for cartridge brass from a materials information data set on Al Harells metals links. http://varmintal.com/aengr.htm#Mats-for-LS-DYNA

It came back after looking at a bunch of cases to be pretty much spot on though I could not really tell by how much either way as I do not have a micrometer that reliably measures to 0.0001".

[montdoug]

Howdy foxhunter .
Larry and I got a couple of the early CZ's and we too were surprised with the measurements on the new factory brass and Mags. The mag as memory serves cause I don't wanna dig the rifle out of the safe says, 17/22 Hornet. The black spacer on the .17 is the same as the standard Hornet magazine.
Measuring the neck of a new unfired factory neck got both of us .193 give or take an occasional .0001 or so. Fired they were quite consistent at .195.
We were both really shocked at how tight that is for a factory rifle and ammo.
After shooting them a bit with the factory ammo we both commented on hoping we could reload ammo as accurate as factory ammo.
That was our experience back when it first came out.
Oh, I was also impressed how close to factory velocity claims mine chrono'd. That's my memory of it new.

[Larry]

Glad to hear you all are getting great accuracy out of your 17 HH CZs.
As Doug says we were very pleased with the accuracy. Dont even want to think about all the initial brass issues.
Haven’t had it out lately so going from memory here.
My neck was nice and tight as Doug mentioned, however the chamber was quite large. In order to avoid overworking the brass I sent my dies off with a few fired cases to Carstenson for modification. Don’t remember if Doug had the same issue.
Factory ammo still sets a high bar. Amazingly small groups.
Love that little gun.
Larry

[JSH]

I am running the 20 grain bullets in mine(527). Case full of 4198 is the accuracy load, still half grain off from what Hodgdon list.
I don’t know what it is doing on speed.

25’s and heavier I launch in the 17R.

[Daryl]

Don't know if it helps or not, but using 1680 and 25g.r Vmaxs in my CZ Ack Hornet - worked very well indeed. My vel. was somewhat higher than the .17 Hornet loads listed.

I chrono'd them in the 1-1/2" longer Pac-Nor bl, but not in the CZ bl. 3,640fps.

[56S]

Originally Posted by JSH

I am running the 20 grain bullets in mine(527). Case full of 4198 is the accuracy load, still half grain off from what Hodgdon list.
I don’t know what it is doing on speed.

25’s and heavier I launch in the 17R.

I like 4198 as well. When the spring arrives I'll try for some chrony readings. Have you tried using small pistol primers? I've seen good results using them.

[JSH]

I have my thoughts on pistol and rifle primers. I use rifle primers in the 17HH, some and I repeat some of my 22 hornet loads I used pistol primers.

[foxhunter]

well 9.86 gr of lil gun seems to be the sweet spot with 20 gr v-maxes and 20 gr hp match bullets. both shot under a dime group at 100 yards. haven't chrono graphed them yet, will advise later.
working with cfebk with 20's and h322 with 25's.

[southernman]

12.5 gr, CFE blackout, CCI 400, and Hornardy or PPU brass under a 20gr v-max is my working load in two CZ .17 hornets. 3650-3700 fps.
I use 12gr BO, as a fireform load with .22 hornet PPU brass,

[foxhunter]

shot some 1680 with 25gr hornady hp today, have to try again . they chrono graphed at 3471 fps I was shocked at the speed.

had better wind conditions and had several sub .50 groups with 20 gr dogtown hp's and 20 gr v-maxes, 3650-3750 fps.