Is my barrel knackerd?


Well-Known Member
So I have had a few issues with my .17 hornet for a bit especailly cold barrel shot misses. I was unsure if this was my homeloads, the Mod the scope etc etc
So I headed up the range with a squeeky clean barrel a load of factory ammo and a couple of mods and the results are below. All shot off a good bench with a predator shooting rest at 100 meters bit of wind but not enough to swing the groups as wind as numbers 1 and 2

Previously the rifle had been a sub moa rifle with a clean barrel

1st .JPG 1st group

2nd.JPG 2nd group

3rd.JPG 3th group

4th.JPG 4th group

Some other groups were shot but were also about 1". Now as mentioned in a previous thread I did despite cleaning the rifle every time it was used have a few rust issues in the bore this ceased when I started making sure I put corrosion protector swab down the bore after cleaning.
What do the Stalking directory experts think? I am angling towards the rusting had pitted the bore somewhere and after its cleaned this is causing accuracy issues but 10 or so shots is filling in the pits and accuracy is returning.

Any guidance / expertise would be gratefully received I so far haven't been able to track anyone down with a borescope that small so that's out as an option for analysis.

If this is the case I am tempted to do a rebarrel as even though its a CZ to buy a new one is about £700 which is about the cost for a rebarrel and at least with a rebarrel I get a semi custom rifle.


Well-Known Member
Nothing wrong with the group in last pick, are you looking to taget shoot or just go for vermin / bunnies if it the latter your gun is fine


Well-Known Member
I'm thinking the same as you.
You could try cleaning with a carbon cleaner like kg1 and leaving the copper in the barrel to see how it shoots.


Well-Known Member
Looks like it likes being dirty as others have said. What about just bore snaking it after use and then not worrying about deep cleaning it?


Well-Known Member
One CAN Over-clean a rifle barrel, I have discovered a near similar situation with my .17Rem. There is a stream of thought held by some quite knowledgeable fellas on YouTube that says ANY rifle barrel has a sweet spot that can only be reached by leaving a certain amount of bullet jacket smeared off into the rifling, and to get anal with aggressive cleaners and hard brush scrubbings is not only counter productive to the best possible accuracy (in hunting rifles at least) but is also potentially damaging in the long run.

I wish I had gotten that idea firmly into my head with the first barrel on my .17Rem, but Over a timespan of maybe four or five years moderate use, I pretty much destroyed its accuracy such that one in maybe 15 test bullets went into my 200yd zeroing paper targets sideways fashion!! I never shot more than 25 at a stretch before getting out the 'Sweets' and my phosphour-bronze brush, and obviously ruined that barrel.. One that initially would give me tight little clover-leaf 3 shot groups with 20gr V-max and H322 powder.

Needless to say I do NOT clean like that any more, and generally have done with three passes of a bore snake close following as possible my last shot of the session.

One thing I DID notice that when .17 20gr & 25gr bullets were available, my rifle shot quite long strings of accurate shots whilst the need to clean - in my particular rifle at least - was noticeably reduced. Wish I could still get 20gr moly'ed projectiles.. But that's progress for you eh???.. Heyho!

Hope these observation help you some Zetter?

Roedeer 1962

Well-Known Member
When i first got my .17 hornet mine was all over the place with factory ammo what i discovered was the jump to the lands is quite a long jump, so i decided to reload my own it turned out it was all most 1/4 of an inch so i reloaded some , next problem they don't fit the mag , so i got a single load replacement to load one at a time , the accuracy increase by 60 % , i took the mag apart and cut the plastic spacer at back of mag and cut it back to the required length all works perfect now with good grouping ............


Well-Known Member
Hi All

Thanks for the advice. I feel a bit better now as I was freaking out a bit I had ruined a barrel after about 700 shots.

On a couple of points and questions asked

1) it was dry patched through before firing
2) Prior to this it had been decoppered and brushed through with a nylon brush. Generally I have patched it through with wipeout and then nylon brushed it to get a lather then let it sit for a bit to clean out then patch through a few more times until clean

3) Yep its a vermin rifle for bunnies and foxes so 1" or below groups at 100 meters is more than adequate.

4) Borescoping is a problem as no one I know or can locate has a .17 one. Someone even asked Edgar Brothers as a favour to see if they could borrow one and they dont have one either.

This was my first centerfire and was new so I took the advice to keep it clean as you are starting from a know point. Obviously this rifle doesnt like that. I think this has been the cause of a lot of my cold barrel misses in the past and why it groups well on the range as generally when I am up the range its because I have changed the scope or am working up a load for the reloads so if the first few are off you chalk it down to not suitable powder charge or getting the scope on zero.

I have after this given it a couple of pulls through with the pull through and put a little corrosion preventative oil on a patch down which I will dry patch out before use. I will try going up the range again with it dirty and cold and see if its on then. If it is then it likes to be dirty.

On the flip side I took up my old Sako 75 .243 I have got as my first stalking rifle off our game keeper. Now this prior to him having it was a forestry commission rifle so you my have guessed that the bore wasnt exactly loved. It was borescoped by Mike at Calton Moore and apart from a bit of pitting looked to have plenty of life in it so I just keep it clean.
Now that is a revelation it basically will put down 1" or below groups all day long with my homeload 85gn soft points, homeload 65gn vmax, 55 gn vmax factory and 80gn soft point factory. All impact at 1" high or as close as damn it at 100 meters which is where I zero at. Its a real confidence builder as whenever I pull the trigger if I do my job the round goes where its supposed to!


Well-Known Member
Do CZ come with a rust kit ? Just add the salt sachet and a few drops of water and soak for a day or 2.

come on, you must surly agree that comment was rather silly.

Zetter no need to bore scope your rifle, it would only upset you. A pity you didn't mention it last time i saw you up Scotland, i had my box of tricks with me.


Well-Known Member
Do CZ come with a rust kit ? Just add the salt sachet and a few drops of water and soak for a day or 2.

come on, you must surly agree that comment was rather silly.

Zetter no need to bore scope your rifle, it would only upset you. A pity you didn't mention it last time i saw you up Scotland, i had my box of tricks with me.

Didnt think of that at the time mate unfortunately I was too preoccupied with the .50 and then the flooded kitchen :D


Well-Known Member
I had a similar looking problem with a .243, it was an intermittent stability problem with the internal workings of the scope.