AusVarmint

G'day All,

Just about fed up with this sort of crap!

Have been through the whole load development process for the CZ550 in .30-06 and have come up with a combination that the rifle shoots consitently (125 grn Speer TNT, 55.5 grns 2208 powder).

Now here is the issue:

The load currently shoots 1.5" low at 100 yds and in excess of 6" high at approx. 200-250 yds. As stated previously this is consistently the case. My ballistics calculator shows that if the load is low at 100 it should be lower at 200 yds.

My thoughts have been that it could be the scope mounts affecting the angle of scope, whereas my old man thinks that it is an issue with the load.

Please offer any help possible - this sort of stuff gives me the s***s! Especially when there are ferals on the other end getting away because of it.

Regards,

CZ550

rear scope mounting ring should be higher if they are of differing heights.

good luck

I think you can discount the load being the issue, projectiles don't fly up, hmm they don't really fly, pretty much fall from the moment they exit the muzzle. I would be trying different mount/ rings / scope.

Ryan

Thanks for the ideas.

I had a look at the mounts etc this morning and the rear mount is approx. 2mm higher than the front. The only issue that I can see is the front bell of the scope may possibly be seated into the front ring making it appear as though the front ring is higher?

It is either this or I have found a gravity defying load!

Will let you know how it goes.

Regards,

CZ550

Maybe try taking the scope and mounts off and starting again making sure everything is in proper alignment. I can't think what else it could be besides a mounting issue!

Its impossible to get that result unless your scope is mounted 6" above the barrel.

the only thing i can think of is are you shooting your 100m groups on a low power (provided of course your scope is variable) then zooming in at 250m? If so I'd say your reticle moves during power adjustment.

Took all the mounts off yesterday and realigned the scope - seating the front of the scope a little further out to ensure that it was not being gripped by the mounts. PITA of a job trying to get the scope just right (i.e. not rotated left or right) so it appears just right to the eye.

The scope is a Leupold VX-1 4-12x40 which I shoot all the time on 12x power. Hopefully this rules out the power change adjusting the reticle side of things - thanks Andrewk

If this fails I may have to look at the bedding / barrel floating. Both seem fine, but may get the smith to check it if its still no good.

Thanks for all the help - I am now out of ammo, so will have to load a few more before seeing if the problem has been sorted.

Regards,

CZ550

it should be easy to see if the barrel is floated

the problem you are describing don't sound like a bedding issue or even a problem with the rifle if the groups are good 1-1.5inches at 100 and 2-3inches at 200 that's fine.

i would be looking at the scope try it on a different rifle be sure the mounts are good.

Got me stumped as to what could be going on.
Is the rifle being shot from the same position, rest etc at both distances is your hold the same.

Only suggestion I can give is sight it in dead on at the range you want (200, 250 etc) and then see where it is hitting at closer distances (100 etc)

G"day,
Maybe it has a crown issue.??
Seems odd though.!!
Regards
Native

If it shoots low at a 100 yards and high at 200 yards and the rifle is of normal configuration then the problem lies with either the organic component or a massive change in barrel/scope/parallax alignment between sessions. Have you shot it in reverse order? Is there a parallax and scope power shift between ranges? Give it to someone else to shoot. Post a picture of your setup.

Your not shooting by resting the fore-end on a hard surface are you?
Cheers...
Con

Thanks for all of the ideas - hopefully will get to the bottom of this one way or another.

The rifle in question has only had around 200 rounds through it at this stage so I hope that it isn't the crown. I will get the smith to check it over when he has a look at it.

I shoot the rifle from the same rest each time (between the A pillar and mirror of the ute). The only thing that fore-end of the rifle (not the barrel) touches from this position is my hand (maybe a problem?).

When I first noticed this problem with the load, I adjusted it to shoot bang on at around 200 yards, with the resulting impact at 100 yards 3" low. I realise that the organic matter in this situation is of limited ability, but when you can clearly see the impact of the bullet through the scope, you feel like you have had a good shot i.e. not flinched or pulled the shot. The results are very consistent too, I get to do a fair bit of shooting with work and have found the differences to point of aim by looking at unfortunate victims like this fox! Lucky it was sitting on end of the barrel at the time.
Thanks for all your help - this sort of thing drives me mad as I think that I like the load, just bizarre what is happening.

Here is a picture of the setup for you to have a look at.
Cheers,

CZ550

Weird indeed. When you get a chance, shoot groups at 25yards, 50 yards, 75yards, 100yards, 150yards and 200yards. Measure the distance accurately. Be interesting to see what trajectory its following. Reason I mentioned resting the rifle on a hard surface is guns can kick away from them, throwing shots higher.
Cheers...
Con

Just thought that I would let you know that this issue has been sorted & no I don't have a gravity defying load!

When I spoke to the smith he said to take the front action bolt out and see if the barrel rose. When I did sure enough it, the barrel rose significantly. When I removed the rear action screw and looked at what was going on the bush that protects the stock from the screw was slightly jammed/skewed between the stock and the action (i.e. not flush with the stock as intended). This appeared to be causing the front of the action to be forced up and the barrel to rise giving the strange sensation of shots rising with distance.

Anyway, thanks for all of your suggestions and help - now looking forward to going and zapping some foxes with it over the next couple weeks. Got 10 on Friday night with the shotty out spotlighting, which has really got me keen to get out soon.

Regards,

CZ550