CZ527 17 Hornet range report...

[Tilleyman]

As promised in the case forming thread, here's Part 2 of my experiences with my new CZ527 American in 17 Hornet... after a seven month wait!

On first unpacking the rifle I was impressed by the overall fit and finish of this new CZ compared to some produced even a couple of years ago... seems the factory has invested in several CNC machines as well a laser checkering station!

As shipped, the rifle had a poor trigger pull... about 6lb with lots of creep.
However the CZ527 trigger is adjustable for release weight, sear engagement and overtravel. The set trigger is adjustable for release weight only.

In pulling the action from the stock, I noticed the action's forward bedding block had been bedded from the factory in a type of epoxy putty... the barrel floated evenly in the channel.

Adjusting the trigger pull for a crisp 2.5lb release unset and a 14oz release when set took about half an hour with a Lyman digital trigger release gauge.
The trigger was finally to my satisfaction so it was off to the range at last!

I could only source one box of Hornady 20gr V-Max factory ammo (Lot #3121399) so this was used to sight in and break in the barrel.

For the time being I fitted a Zeiss Conquest 3.5-10x44mm scope with a standard Z-Plex reticle which I had intended for a .270W. It fitted well into the factory mounts, with the bolt handle easily clearing the ocular housing.



What struck me during the barrel run-in process was how little the CZ's hammer forged barrel copper fouled. Barely a trace of blue using Boretech CU+2.
It did however powder foul a fair bit using Hornady factory ammo... which I've found to be pretty filthy in other calibres too...

One of the nifty things I've discovered in cleaning my first 17 calibre rifle is that ordinary cotton buds made for cleaning ears can be cut in half and precisely screw into the end of my BoreTech cleaning rod.
I love being able to buy 800 cleaning patches for $4.50 at Woolies!



Using my new Magnetospeed V1 chrony (Santa was generous this year!) the Hornady factory ammo grouped about 1.25" with some lateral spread. Not helped by the notoriously changeable wind from L to R at Little River range!
The barrel mounted chrony showed:
3496fps
3479
3501
3469
3521
For an average of 3493fps

Changing over to my PRIVI fireforming loads...
Using a 20gr V-Max in front of Hodgdon Lil Gun powder, Federal 205M primer:
9.6gr (avg 3587 SD 15)
9.7 (avg 3593fps) ** most accurate **
9.8 (avg 3659fps SD 28)
10.0 (3706fps SD 34)



Using a 20gr V-Max in front of Win 296 powder, Federal 205M primer:
9.4gr (avg 3319fps SD 49)
9.6gr (avg 3407fps) ** most accurate **
9.8gr (avg 3450fps)
Note I obtained these loads from am Australian shooting magazine, but I've since realised they are well above the Hodgdon max of 8.7gr listed in their online reloading guide for the 17 Hornet.
It is however within the limits of load data obtained direct from Hornady.
No pressure signs evident, but beware of using this load in your rifle!



As an experiment I also tried some reduced loads using Trailboss and a 20gr Berger FBHP...
Using the ADI guideline of filling the case to the base of the bullet to develop a maximum (3.5gr) and then multiplying by 0.7 to develop a minimum load (2.5gr), five unfireformed PRIVI cases were loaded with 3.0gr, 3.2gr and 3.5gr Trailboss.
Unfortunately my new Magnetospeed would not register these much slower bullets until I altered the sensitivity of the magnetic trigger low enough!
So only have data for the 3.5gr load:
1880fps
1147fps
1924fps
1278fps
1397fps
Clearly there is something wrong here, as the loads were carefully individually measured out... perhaps the chrony was inaccurate at these low speeds, but the whole exercise was disappointing.

Using a 20gr V-Max in front of ADI 2205 powder:
9.3gr (avg 3136fps SD 41) ** most accurate **
9.5gr (avg 3210fps)
9.7gr (avg 3284fps SD 13)
10.0gr (avg 3403fps)

None of the ADI 2205 loads showed any real accuracy nodes, and velocities were slow so this powder will be dropped from further load development.

Most promising load so far was 9.7gr Lil Gun behind a 20gr V-Max for 3593fps.
I'm a little wary of using Lil Gun in the 17 Hornet as I've heard of some pressure inconsistencies as max loads are approached.

Next range trip will include tests of ADI 2207 and Vihtavuori N120 as this last powder appears to offer the highest velocities at the lowest pressure... if I can locate some in Melbourne!!

Anyway, hope you have found this range report interesting... I'm really enjoying my CZ527 17 Hornet!

[Dean2]

Pressure excursions with Lil'Gun are the result of the same thing you get excursions from in other powders. It is a fast powder, so at max load in a small case, even 2/10s too much powder, caused by throwing rather than measuring the loads, can be a problem. 2/10s too much when you are a 1/2 grain or more below max is no problem at all. This is true of a lot of powders.

Also, loading right at the ragged edge of max in small cases, heat becomes an issue, as does consistency of primers, case capacity etc. I have used Lil'Gun for years in 22 H, 221 FB and 218 Bee. The hornets I load at 12.6 grains, thrown with a Lyman 55, for 3100 fps with a 40 grain bullet and a Federal small pistol primer, so quite a ways off max. The 218 and 221 are much larger cases and not nearly as sensitive, so I load both of these very close to published max. I have NEVER had a pressure excursion in literally 10s of thousands of rounds in those calibers.

[XA-Coupe]

Nice report. I will have to take mine out to Little River to check for accuracy, though I am stuck with the factory rounds for the moment. I will look forward to the other handloads you want to try as I will reload when I get around to making enough empties.

[Jeremy(WI)]

I was able to get a .4" group at 100 yards with Hornady factory 20Gr ammo and with handloads using hornady brass, 20 gr VMax with 9.6 gr of VV N110

I have tried trail boss in quite a few cartridges, most about case full of powder and see a large variation in velocity. I still like using it even if I never get any accuracy from it

[Tilleyman]

Jeremy
So you found VV N110 better than VV N120?
Heard rave reviews about VV120 in the 17 AH and figured it would be the go-to powder for the 17 Hornet as well.

Didn't realise Trailboss had such wide variations in velocity, maybe there is nothing wrong with the Magnetospeed after all

[Jeremy(WI)]

Originally Posted by Tilleyman

Jeremy
So you found VV N110 better than VV N120?
Heard rave reviews about VV120 in the 17 AH and figured it would be the go-to powder for the 17 Hornet as well.

Didn't realise Trailboss had such wide variations in velocity, maybe there is nothing wrong with the Magnetospeed after all

I haven't been able to find N120, Lil Gun, or AA2200

When it warms up I plan on seeing what accuracy I can get from my AA1680

[L Cazador]

I'm just in the process of breaking in my CZ 17HH and I got a pleasant surprise too with very little copper fouling. Bore scope shows a pretty smooth barrel, definitely not like a custom barrel, but smoother than most factory barrels. I don't like the bedding. The rear screw has a pillar but the front does not. Did they leave one out? My thought is to leave it as is till I finish fireforming my PRVI brass. The PRVI brass has worked very well for me. I'm single loading ammo out of the magazine even though it's a pain. I found that 9.5g of 1680, Federal 205M, and 25g Hornady V-Max loaded to touch the lands fireforms very well with 3/4 inch groups. I have already altered one magazine to accept the longer COL. BTW my NECO ballistics program indicates that LIL-Gun is way too fast for my 25g V-Max, so that may be the same for the 20g pills.

[Dean2]

Originally Posted by L Cazador

BTW my NECO ballistics program indicates that LIL-Gun is way too fast for my 25g V-Max, so that may be the same for the 20g pills.

I would say your NECO program is off by a bit Hodgdon has published Lil'Gun loads of max 10 for the 20 and max 8.9 for the 25 Vmax, though they do not show a Lil'Gun load for the 30 grain, only slower powders.

[L Cazador]

Originally Posted by Dean2

I would say your NECO program is off by a bit Hodgdon has published Lil'Gun loads of max 10 for the 20 and max 8.9 for the 25 Vmax, though they do not show a Lil'Gun load for the 30 grain, only slower powders.

Yup, I saw that info that Hodgdon posted. Since I had both powders, and since the NECO program posts a much lower pressure for 1680, I decided to go with it. I don't like pushing things to the limit. I like my cases to last a while after all the work I put into them. I haven't gotten into full loads yet but both powders should perform the same on full loads as well, save for the higher pressure with LilGun.

[Daryl]

My .17H loves Lil'Gun - actually both of my current .17AH barrels love Lil'Gun and both I figure max. out at 10.3gr. depending on brass make My first AH barrel and my buddy's AH's maxed out at 10.8gr.- WAYYYYYY too much for the CZ or Pac-Nor.

In the even smaller case of the .17HH - I'd probably stay below 10.0gr. & perhaps in the 3,550fps max. range.

I have never had any pressure problems with LG in the .22 Hornet, .218 Bee nor 3, .17AH barrels as I started low and developed loads based on what I could measure in case expansion and see/feel, with my eyes and hands.

Note RWS brass has the smallest case capacity, following WW which follows RP - RP having the greatest capacity and the longest surviving brass (between WW and RP).