Issues are possibly:
Poor zero
Wind
Cant
Bad scope
Or a combination of multiple
Issues are possibly:
Poor zero
Wind
Cant
Bad scope
Or a combination of multiple
But. To have 130mm of windage from cant at 400m - you'd need 15-20 degrees of cant. You would need to be blind to accidentally have that. 1 or 2 or 3 degrees, sure. Which gives 2cm of error.
It likely isn't cant.
Maybe it is just you ? who is at fault . Shooting further out has a tendency to show up all those things that we tend to get away with when were only shooting up close and personal . One give away is that the error is not consistent , but then again the wind can be a real deceitful bitch .
Last edited by Tankd; 30-10-2024 at 07:18 PM.
For shooting past 350M or so you're just about wasting your time with anything less than a zero based on 10 shots - either to prove the rifle will group, or to actually zero from. Having said that heaps of people can still get a deer at 350 ish because "minute of deer" at that range is at least 250x250mm which is about 0.7 5Mil or 2.5 MOA and just about all decent rifles will do that, even 303s.
Where's your 100m group poi? Dead smack centre of the bullseye? If not there could be some of your error. If it's 15mm out at 100 then that very quickly becomes 30mm at 200m and so on, which would give you 120mm at 400?
If not dialling, scope not in true line with the bore. Could be several reasons for this, barrel not correctly aligned with the receiver, receiver mounting for the scope mount not aligned, mismatched rings, internal issue somewhere where it is shooting walleyed or pigeon footed but the last isn't likely.
Or, there's an outside chance that there is an internal error in the scope in that the internals of the scope aren't in line with the external tube or the scope is physically bent...
It doesn't need to be a huge error to create this sort of issue - but there is a reason for it and if you can repeat the results with different trigger pullers and on different days it ain't the puller.
An anology to this is the first attempts at military scoped rifles where they wanted to retain the functionality of the basic rifle, iron sights and charger loading and the scope was an additional aid for the marksman. To do this, they offset the scope to the left of the receiver leaving the top of the receiver open to allow access to the charger guides and the iron sights. Mounting the scope to the left meant that it had to be aligned at a known range and at shorter ranges the POI was left, longer it was to the right. Your situation is not quite as extreme but identical, it's now a case of finding out why.
Thanks a lot you guys. I'll get a real shooter to see if he repeats my results.
If scope/base is not perfectly parallel to bore,eg it's slightly off to one side.the rifle zeroed at hundy will be off at two hundy...but typing that out it can only be out by same fly shit amount. If your rifle is kinked to the side,yes it will be off to side...and in theory slightly lower than expected too. Don't overthink it.130mm at 400 is not a huge amount.5" if it is a consistent thing you can compensate. Repeat test again twice and report back with results lol
75/15/10 black powder matters
If your scope is only 2 degrees off plump with bore centre.Scope and rifle bore height 2 inch radius.At zero yards yr true bullet hole will only
be 5.728mm to the opposite side of vertical plump line.At a 200yds of yr bullet holes will be off plump to the opposit side 5.728mm if you are zeroed at a 100yds.If yr scope was 6 degrees off plump you'd see if with one eye shut.At 400 yds you are drifting to the say right 17.81 mm (2 degrees off plump)for a start,I'd be happy a 100mm.
At 400 yds it ony takes a slight breeze to drift 130mm,that includes shooter error,scope aligment,trigger pull,the list goes on.At deer at 400yds is a big target,sholder 10 inch circle broad side.
Get the hundred yards near perfect,I cant but close.
Sorry 2 degrees should be 2.25mm on circumference of a 2inch radius circle.Correct me if I'm wrong,morning maths not that good.
See if it happens a second day.
Post some photos of the targets with a grid cm scale.
If you only fired 2 shot groups you’re wasting all these peoples time speculating.
Well with a Tikka and Optilocks it is not a problem with the mounting system it is the best factory setup there is, if the scope is ok is mostly likely shooter error
or the bedding has gone off, I would shoot a 5 shot group at 200 metres off sandbags; bipods are not the best to shoot off a solid bench they bounce, the torque
from the rifling can throw the shot in the direction of the twist.
Your rifle is not sighted in properly. You now find it shoots to the right, after testing it at 200 and 300. So zero the rifle properly at 100 and fire four or five shots to check zero. (Do this after considering the below*)
To answer your other question, if you are leaning into the rifle one way and then holding it back on target, then yes it probably will shoot off. You can often tell that as the rifle will also recoil away to one side.
You should find out what the Natural Point Of Aim*is, and accomodate this in your shooting, and it will solve what you are talking about. It's basic shooting technique. There will be videos on Youtube. I thought that I invented it myself, but I then found out that people have been doing it for years.
Last edited by John Duxbury; 07-11-2024 at 02:05 AM.
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