CZ 527 17 Hornet - .5MOA Best It Can Do?

[toasty]

I have a CZ 527 American in 17 Hornet. Shot several hundred rounds through this gun over the last couple years. It shoots factory Hornady 20gr Ammo at .5 to .7moa pretty much all the time. I have been reloading for about 15 years and have tried 2 different bullets with 5 different powders over the last year looking for something that shoots as good or better than factory ammo. Finally found IMR 4198 to be the ticket and regularly get .4 to .5 moa groups when there are perfect shooting conditions. I know it is not me as I can shoot .25" groups with a couple of my best guns on the same day. Is this the best I can hope for with the sporter barrel gun?

 

[Oso]

The CZ527 sporter barrel is a light weight contour so you just have to really keep an eye on shot rate to avoid heating up the barrel. I have traded out of all of my CZ 527 sporter rifles in favor of their heavier varmint barrel contour, which is still like a medium varmint when compared to the heavier Remington Varmint contour.

If the rifle is in the factory walnut stock then you want to pillar/bed the action, which should improve your group size.

 

[Tommie]

Half MOA with a bone stock gun is pretty darn good. Just sayin’

 

[08glide]

Any chance you tried VV N120 in your CZ? That powder in my CZ with 20 grain bullets really shined! I tested a lot of powders with that rifle and the testing ended when I tried the N120.

 

[dstoenner]

I have the varmint barrel version and mine shoots about average of .4 with .3 scatered in the results. Like you i had tried a lot of bullets and powder combinations. I settled on CFE-BLK as the best powder with AA1680 second. Best bullet is the Hornady 15.5 NTX and in second place is the Berger 25 FBHP. I pillar bedded my rifle and put in the Rifle Basic trigger to get away from the set trigger. Now i am down to about1.5#.

it also took about 400 rounds before the barrel settled in AND it would clean up easy. For me getting that bore clean took a couple of days. Mine maybe the oddball but it shoots wonderful. I was almost ready to rebarrel it in 221 FB but it got better so I dropped the idea. I just love the micro Mauser action

David

 

[roband]

^^^^ Getting the bore clean took a couple days....
Purchased a 527 in 17 Rem that had only been shot five times,well those five shots cooked whatever CZ uses to protect their barrels.Man what a deal i about quit a couple times.Crazy thing about it, it shot a nice little cluster both pre and post cleaning???Go figure.

 

[B23]

I've had a handful of new CZ 527's and I'll be damned if I know what CZ puts in the barrels from the factory but it is some nasty stuff. I think it's a mix of honey, old burnt axle grease, 150wt gear oil, black coal tar and a few drops of Gorilla glue because it is the thickest stickiest crap I've ever had to clean out of a new barrel.

The first couple CZ's I got I took the conservative approach and spent way longer than I'm willing to admit patching that crap out with Butch's. Then I said screw it and just started using brake cleaner. Pull the bolt, tip the gun barrel down into a drain pan, stick the little red straw thing from the can of brake cleaner in the chamber and watch that black tar crap run out the end of the muzzle. About the time the can gets empty the fluid starts running clear. Then I'll patch it dry, patch it with Butch's, patch it dry again and go shoot the thing.

I have a couple CZ 527 Varmint model 17 Hornets. If you have a load that can regularly get you .4 - .5 groups with an untouched off the shelf factory gun I'm not sure there is a lot to complain about.

I'm not sure how light you have the trigger set but changing the spring in the CZ 527's is very easy to do and will allow you to get it well below 1lb without using the set trigger. I personally don't like using the set trigger it causes me to disrupt the gun to much pushing the trigger forward when I'm setting it as well as puts the actually trigger in a odd location for me so I replace the trigger pull rate spring and have all mine adjusted to right around 10oz without using the set trigger. From a bench a lighter trigger and not using the set trigger could tighten up your groups slightly but again if you can regularly get .4 to .5 from a box stock CZ 527 17 Hornet, that's pretty darn good.

The CZ 527's, at least all of them that I've ever had, come with a pillar from the factory it's just not glued in place.

 

[toasty]

Thanks for all of the feedback. The gun is not new and I have thoroughly cleaned it at least a dozen times in the past several years and the first time did take me several hours to finally get a clean patch, so I don't think it is new grease. I currently have 400 rounds through the barrel, so I am thinking it is mostly broken in. I have seen my accuracy start falling off depending on powder at about 30-35 rounds. My best groups come in shots before that 30 shot mark. I shoot a lot of HBN coated in other calibers and that has shown to extend accuracy for more shots between cleaning, but not tried HBN coated it this 17HH. When are you guys starting to see groups open up?

I have tried CFE Black and it is my second best powder, it was matching factory 20gr Hornady accuracy, however, occasionally I would get a really bad group out of nowhere. IMR 4198 is best so far and very consistent day to day. It just shoots .4 to .5 groups, never better, never worse than .6 moa. I have also tried, H110, Lilgun, AA1680, and H322 (not enough powder can fit to get over 3500fps). I have not tried VV N120, I will put that on the list if I ever am able to find a lb of it. With IMR 4198, it fills the case and I vibrate it and the powder ends up the almost the base of the neck. Anyone know how much more H4198 I can fit in the case?

Anybody want to share seating depth? I am running the 20gr hornady at 1.763 and I get a .5moa vertical string and at 1.760, I get a .5moa horizontal string. At 1.7615, it is mixed, but never better than about .5moa.

As far as the set trigger, mine breaks at about 14oz. I like the trigger, but you're right, I sit up to reset it. You're saying that having to move to reset the trigger is changing my cheek weld, sight picture, etc... and causing additional accuracy loss?

 

[B23]

You're saying that having to move to reset the trigger is changing my cheek weld, sight picture, etc... and causing additional accuracy loss?

I can only speak for myself and for me pushing the trigger forward would cause me to move the gun a little, which I try not to do once I have it positioned, as well as I didn't like the position it put the trigger in.

The trigger in the CZ 527's is not only easy to work on but can be adjusted for pre/over travel, pull weight, and sear engagement. I bought my replacement springs for all my 527's from James Calhoon. He only charges a couple bucks for them and if you give him a call he'll probably tell you how to use a spring from a Bic lighter. James is a real character to chat with and kind of specializes in most things CZ 527 related.

OAL and seating depth, unless you single feed, your limited to mag length. These CZ 527 17 Hornets have quite a bit of freebore in them from the factory and the bullet will damn near fall out of the case before you can touch the lands.

 

[PigButtons]

I don't own a CZ of any flavor, but I do own several 22K Hornets. What I've found out in the last two weeks since I purchased an A&D Fx-120i scale ( and I have no affiliation with the company ), is that loading accuracy makes a huge difference in these small caliber, micro cartridges. Weighing charges before to +/- 0.1 gr and now to +/- 0.02 gr, and bullet sorting now to 0.06 gr, has taken my group sizes from .5MOA to .2MOA on both of the first 2 Hornets I've loaded for since getting the scale. The smaller the size the more precision counts.
I never would have even thought of such things without this site and all of the really good shooters here. Thanks to you all.

 

[B23]

I don't own a CZ of any flavor, but I do own several 22K Hornets. What I've found out in the last two weeks since I purchased an A&D Fx-120i scale ( and I have no affiliation with the company ), is that loading accuracy makes a huge difference in these small caliber, micro cartridges. Weighing charges before to +/- 0.1 gr and now to +/- 0.02 gr, and bullet sorting now to 0.06 gr, has taken my group sizes from .5MOA to .2MOA on both of the first 2 Hornets I've loaded for since getting the scale. The smaller the size the more precision counts.
I never would have even thought of such things without this site and all of the really good shooters here. Thanks to you all.

I have the same scale and when measuring small powder like 1680 it is much more sensitive to tiny changes. If I trickle in with my Chargemaster it will take what seems like a lot of powder before it registers any amount of change on the scale but I can trickle in with the FX 120 and very slight changes will register a change on the scale.

 

[Kittitas George]

I have a 17 Hornaday Hornet, Ruger #1, and Lilja barrel. I'm getting my best groups with AA1680. At about 25 rounds I run a patch or 2 thru the barrel. Some of the other powders I've tried seem to foul faster. Like the gentleman above, the factory loads are shooting better groups. However, I did get a couple of Montana gophers at 250 yards and some closer with hand loads. Now that the weather is warmer I'll get those groups tightened up. One hole is the goal !!

 

[1raggedhole]

If you use a ballistic calculator to check wind drift at 100 yds, you will quickly see that those little bullets drift with even a slight breeze. 1/2 moa is excellent with any 17.

 

[TheOtherZilla]

I have one. Can't remember how tight it shoots but it's tight enough to waste p-dawgs all day. 2200 powder is what I use. Either a Hornaday Vmax or no-name Midsouth cheapos. Mine too is the varmint version.

 

[searcher]

Getting the best accuracy out of the .17 hornet takes a bit of work in my experience- but is well worth it. Must weigh individual charges on a scale capable of better than 1/10th grain. While turned necks tend to help about any cartridge to some degree - the smaller the neck - the better the result - and turning does wonders for the .17 hornet. Must also use a primer with a relatively soft cup. I use CCI400's. These are my favorite loads. I don't go for super fast - but rather super accuracy. These work WAY under 1/2 " MOA in mine.
20 grain V-Max (moly coated), 11.5 grains H4198, CCI 400, .020" off lands, 3,390 fps
20 grain V-Max (moly coated), 9.3 grains IMR4227, CCI 400, .020" off lands, 3,175 FPS (best)
25 Berger (HBN coated), 10.8 grains H4198, CCI400, .020" off lands, 3,136 FPS

The necks are turned to 90% clean metal and very carefully inside reamed with a VLD-type reamer.
the .020" off the lands measurement is 1.478" length, measured using the Hornady tool on the dial caliper. Sorry - I don't record OAL measurements.
Good Luck!

 

[TheCZKid]

I have a CZ with varmint barrel, thinking about bedding the action next. Mine shoots well with Fed American Eagle 20 Vmax best averaging .40" normally, not as well with Hornady Superformance, average .60" to 1.0". I've tried various seating depths, and various primer options, and so far mine likes 20 Vmax with Remington 7 1/2 primers, current seating depth same as factory Fed AE ammo, 1.699 COAL. Since getting powders is hard right now I'm limited to CFE BLK and AA1680 mainly.

This caliber has a LOT of variables to try to figure out, so it's been somewhat difficult compared to most other rifles I've loaded for. As others have said, the accuracy of the powder charges in critical, so I purchased the A&D EJ-54D2 scale, which is able to go to .005 grain accuracy, but is slower to settle than the FX-120i, and its a little less expensive too. I use the RCBS Chargemaster to throw .1 grain less that what I'm trying for, then move to the digital scale, use a "Dandy Trickler" to bring the load to the exact charge.



Now I'm also trying turning the necks with my Hornady neck turner, after getting the .17 mandrel and proprietary shell holder... turning is somewhat new to me, and makes me a bit nervous. The necks are already thin. But I'll be trying new tests when I get a calm day.

 

[TheCZKid]

A have a couple questions, #1: Anyone use a LEE Factory Crimp Die on the 17 Hornet? My buddy does always on every caliber, and those that do use it seem to advocate for it. But most reloaders have not ever tried one, and don't mention it in posts (though I've seen a few that do with the 17 Hornet). Now that I'm trying the neck turning option, it seems like the neck tension should be consistent and not need the FCD.

Question #2: How often do you anneal your brass? I know some who shoot competitively say after every shooting, others maybe after 3 or 4 times... With the necks turned they are thin (they are already thin!), and I don't want them to be work-hardened and thus either start to crack, or have the neck tension change due to multiple sizings.

 

[dstoenner]

1) yes. I think it evens out velocity giving lower es/sd

2) never. I loose too much brass with seating bullets that go wonky that i am never going to get a lot of reloads on them. Plus i have no annealer

David

 

[JSH]

Played with mine enough.
Honest average I will say is 1”@100, that is day in and day out, with what ever ammo combo I happen to grab.
Yes it has shot smaller groups. Come home and load up a hundred just like it, and then it shows no better.

Turning necks, I would be making my own brass from 22Hornet.
You may well need to use a factory crimp on neck turned brass.

All my 17HH gun and gear will be leaving as soon as I shoot up the hand loaded ammo that is left.
I get better results,quicker and easier with the 17 Fireball.

 

[TheCZKid]

1) yes. I think it evens out velocity giving lower es/sd

2) never. I loose too much brass with seating bullets that go wonky that i am never going to get a lot of reloads on them. Plus i have no annealer

David

Thanks for your reply. I'll try some with and without the FCD, see if it makes a difference.

I did find out something last night... I assumed the Hornady bullet seating die, with the bullet aligning collar, was seating my bullets pretty concentric.
I checked my newly loaded neck turned cases and loads I made last night with my RCBS Case Master. Turns out the seating die has been bending my cases at the neck to one side, about .008, the tip of the bullet wobbles around in a circle.
The brass before seating was .001 on average. I was amazed! I checked my non-turned test loads I prepared earlier, and all those are also bent too, off concentricity at the neck forward by about .008.

So I ordered the Redding Competition Seating die, MidwayUSA $148, dang! $$ That might be one big issue for the inaccurate and inconsistent of my test load results so far.

On #2, I have annealed other brass using the Hornady Anneal Kit #041220, they're like a socket on the end of a 6-sided bit which fits a drill motor, and you just spin the brass over a torch, using Tempilaq 475 degree temperature indicating liquid, to find correct distance from and time over the flame. I have not tried it on my 17 Hornet brass yet, might need a smaller diameter bit. Here's the kit, and I use a propane torch.