Registered User
Hi,
Apologies for posting yet another question about setting up a scope but any comments or advice would be most welcome. Here goes:
Being a born again airgunner I have just bought a pcp outfit ( A Daystate Regal in .177 and an MTC Mamba Lite 3-12x44 scope fitted with BKL mounts ). At the moment I haven't got round to actually shooting it at a decent range to zero it in, but I have a few questions before I do.
In my early airgunning days I just fitted the scope with the correct eye relief and the cross hairs perpendicular by eye and away I went, however, now with the advent of the internet you can easily become overloaded with information especially around fitting scopes! I have read loads about fitting scopes but the one thing I keep coming back to is the alignment of the scope to the barrel (when viewed from above), the chances of this being correct from the box is minimal as there are so many tolerances to take into account such as the barrel alignment to the action, the alignment of the dovetails to the action, the scope mounts and the scope itself to mention a few. Anyway, if the scope is not aligned with the barrel you get the dreaded "crossover" whereby the windage varies at different ranges, for example: you may zero bang on at 25 yards but at 10 yards it shooots to the left and at 35 yards it shoots to the right. I know that parallax and canting can give the same affect, but I am concerned about scope alignment at moment as the other two are easy to fix!
I have spoken to a number of people at my club about this and most don't seem to bother about optically centering the scope then shimming the mounts to achieve windage zero at all ranges and yet they seem to cope ok.
The answer to this seems to be adjustable mounts, the problem is, on the Daystate Regal because of the magazine it isn't possible to fit them (I think ) and I do not like the idea of shimming due to the risk of damaging the scope.
Just wondering how yourselves have overcome this problem, or has it not been a problem! I am tempted to just zero it at say 25 to 30 yards and then see how far (if at all) the windage varies at other ranges.
Any comments, advice, experience etc would be most welcome. Sorry for long posting!
Andy
Registered User
Use a plumb line but you also have to ensure the gun is gel at a perfect 90 degree angle which isn't easy.
I just get it as good by eye as possible and zero it to 25 yards then shoot at 10 and 40 yards and keep adjusting the scope till it's central at all distances.
You need to do this at an indoor range preferably as wind is a pita.
Registered User
I believe the daystate Regal has a Flat top receiver, Just get a known good level across the Receiver, Then a plumb line, (makes it easier if you have someone to keep an eye on the level),If you have a bolt on level ,This type of thing https://www.google.co.uk/search?q=bo...ml%3B225%3B147 ,Then you must check it with the level across the receiver mentioned earlier, as when you bolt one on there is no garrentee that it is on level,,Hope that is all clear,, I.E. A known good level,is one that you have tested by putting on a flat surface an then spinning around 180 degrees, an it should show the same..
1 Rapid+sentinal n/v, 1 HW100+ Mamba lite
Registered User
As above really. Use a plumb line to ensure cross hair is vertical and then your 8 yard and 45 yard aim points will tell you if your not spot on ( assuming no wind).
Good mounts (which bkl are) and good rifle (which again you have) will avoid cross over.
Stop thinking and start shooting
If you havnt already, join a club. Best thing I did and hands on help is much better to written help
Si
Registered User
Getting the cross hairs just right is a bit of a pain. I always wonder why scope and scope mount manufacturers dont print a line along the scope tube parallel with the cross hairs? might help a little.
hoplophobe
Even older than BTDT
I used to be obsessed about crossover, and posted some absolute rubbish on here.
The only common occurrence is if you knock the barrel of an S400, for example, and you try and correct the POI with the scope. Cant is the real enemy..! As said, it can be easily corrected with a good spirit level on the dovetail, and a plumb line. Any scope benefits from being set up at optical zero, as it is then operating with minimum error due to chromatic and spherical abberations, white out, etc. I always use adjustable mounts. An adjustable cheek piece and scope maximiser keeps your eye in the same place, reducing parallax error.
Gus
The ox is slow, but the earth is patient.
Registered User
Every rifle, and mounts might be slightly different so the line wouldn't be central anyway. Plus they probably wouldn't get the line in the right place every time anyway due to manufacturing tolerances.Originally Posted by Hollowpoint
Registered User
It would give some sort of starting point though surely.Im sure they could get it more accurate than "about there"
hoplophobe
Registered User
I think your starting point is looking through the scope and making the decision that it's central to the rifle.It would give some sort of starting point though surely.
I suppose they could also make the line raised (brail style) for blind shooters 😜
Registered User
The barrel SHOULD be correctly aligned in the block and the dovetails correctly machined, either way there is little that can be done to correct any manufacturing defects.
The thing that causes most crossover error is the use of mounts that are fixed on one side with a clamp on the other.
As you have BKL's you don't have that issue, your mounts are self centring so they will self align with the block.
In all likelihood your scope will be within 10 clicks of horizontal alignment straight from the box, vertical will be further out but that depends on what rifle it's fitted to so can't be factory set.
Registered User
Just think about crossover for a minute.
Imagine your scope were mounted 1mm off to one side of the barrel; a larger amount than I have seen with any quality mount.
You zero at 35 yards and shoot at a target 50 yards away. The pellet will 'crossover' 15/35 of 1mm. Or about 0.4mm. Not much! At 10 yards it will be 25/35 mm. Also not much.
The important factor is to have the cross hair above the barrel when you aim.
The easiest way is to set your parallax to its minimum, let's say 10 yards. Stand 5 yards in front of a mirror and aim at your reflection. (Lots of warnings about unloaded gun, be safe etc etc) You can easily see if the lower vertical part of the cross hairs bisects the barrel muzzle. ie the cross hair is above the centre of the barrel. Now, as long as you hold the cross hairs straight when you aim, Bobs your uncle.
Most of the time when you think you are suffering from crossover it's usually your eye position causing parallax error!
Anyway, just my thoughts...
Registered User
Good post PK,, with the proviso,i think most problems are Cant,,,, with the scope not set (dead) right.
1 Rapid+sentinal n/v, 1 HW100+ Mamba lite
Registered User
The BKL mounts you've got fitted should all but eliminate the problem of scope too bore alignment !...
Registered User
Many thanks for all your advice, I have already set up the scope with a plumb line and spirit level. I am off to the shooting club on Sunday to give my new baby its first blast!
Cheers
Andy
Work is the refuge of people who have nothing better to do
I have a Nikon scope with exactly this feature, don't know why its not on all scopes to be honest.
Kindest regards
Barrel
IF I WALKED ON WATER PEOPLE WOULD SAY I COULD NOT SWIM !
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