Rimfire mounts?

[Born Hunter 17,639]

Im using the hmr more this year and need it to be ‘right’ like the centre fire. Im sick of having to rezero after missing sitters. 

Its a 20” cz455 with vortex viper 30mm scope. Im assuming my problem is the 30 quid air rifle mounts but could be wrong. It’ll shoot nice for a day and then one day, probably after a knock be 4” off. Everything is tight.

Thoughts?

Picture because we all love a picture.

 

Edited June 2, 2023 by Born Hunter

[walshie 2,804]

Could be loads of things. £30 mounts should be ok for a rimfire. Could be the barrel moving in the stock, the scope itself or you're a terrible shot. 

Start with the cheap solutions. First thing I'd do is swap round the front and rear mounts to see if that makes a difference. 

[Born Hunter 17,639]

23 minutes ago, walshie said:

Could be loads of things. £30 mounts should be ok for a rimfire. Could be the barrel moving in the stock, the scope itself or you're a terrible shot. 

Start with the cheap solutions. First thing I'd do is swap round the front and rear mounts to see if that makes a difference. 

It’s unlikely to be me because it’s systematic shift that requires a rezero. Same story with ammo.

I can switch the mounts round but what is the mechanism of failure that that will help with? Surely if there’s failure one way round then there will be the other?

Cheers 

[Born Hunter 17,639]

Action/barrel moving within the stock scares me lol. 

[Born Hunter 17,639]

15 minutes ago, Born Hunter said:

Action/barrel moving within the stock scares me lol. 

On this I suppose I could test it by moving the barrel around between magazine refills to see if the zero shifts…

I still reckon the mounts are wank though. Recoil isn’t the only thing they have to resist.

[walshie 2,804]

49 minutes ago, Born Hunter said:

It’s unlikely to be me because it’s systematic shift that requires a rezero. Same story with ammo.

I can switch the mounts round but what is the mechanism of failure that that will help with? Surely if there’s failure one way round then there will be the other?

Cheers 

The operator error was a bit tongue in cheek, but it's best to start with the cheap stuff like swapping the mounts front and rear and/or rotating them 180 degrees to see if the issue is with the mounts or any differences between the two.They might grip better one way than the other or you might not be able to do it at all if they have locating pins on.

47 minutes ago, Born Hunter said:

Action/barrel moving within the stock scares me lol. 

Might be something as simple as a loose screw.

 

[scarecrow243 24]

if all the screws are tight  the next time you zero it make sure the barrel does not get hot  it can even with two or three shots in sunny weather  if its ok and zeroes ok then leave it in the shade till the barrel is cold then try a zero shot to see if its still on target   if you are sitting in the sun shine it will heat the barrel we had this problem at the range first  2 shots  bullseye  3rd shot high and right this happened to 2 different rifles  .243 &  .308

[Deker 3,453]

Sportsmatch!

Just the same, I would consider other things first as already mentioned, and regardless of make, I would check/swap scope, just to check.

[comanche 2,799]

Put a line of Tippex round the mounts and see if a crack appears after a few shots .

[FLATTOP 3,679]

Just out of curiosity do you clean the barrel and the silencer a lot my 15 years experience of owning a Cz 452 .17 has taught me they don’t like being cleaned, obviously you have to clean them now and then but when you do you have to wait for them to settle down normally about 10 shots, also stick to the same ammo that it likes my go to ammo is Remingtons people will come on and say HMR is all made in the same factory with different names but trust me they shoot differently.

[Metalman2 45]

Is the barrel Free floating, my last three CZ’s needed the stocks sorting. I would assume the locking screws for the barrel are ok

[PLEDGEY 493]

I have a CZ 452 .17. Only ever put a bore snake down it. When I first got it it was shooting all over. Ran a ten pound note between the barrel and stock and the barrel was touching the stock. Took it apart and ran a Dremel over the stock so the barrel was floating better. Added a cheek riser and I'm happy with it now.

[Metalman2 45]

I have Pic rails on all my FAC now and use Burris Signature Zee rings

[Deker 3,453]

Did you ever find the problem?

[Born Hunter 17,639]

6 hours ago, Deker said:

Did you ever find the problem?

No, the year has moved on and I’m not using it as much. Until spring ‘24 when I expect I’ll have the same problem.