wildfowler.250 Posted April 9, 2009 Report Share Posted April 9, 2009 Hi I was just wondering if anyone could explain the following situation :blink: Theres been a few times when I have been out shooting rabbits with the HMR, (using a variable scope) and I have zoomed into 20x and missed rabbits clean when I'm sure I'm on them ? This happened again last night and then I went onto shoot 3 at similar distances at 8x magnification.... Anyways I was just wondering if changing the zoom affected the point of impact or do you cover the rabbit with the cross hairs better or something with a lower zoom? Sorry for explaining it so poorly but hopefully it makes sense... Any comments appreciated Quote Link to comment Share on other sites More sharing options...
garyb Posted April 9, 2009 Report Share Posted April 9, 2009 The POI moves as you adjust the mag Quote Link to comment Share on other sites More sharing options...
realtreedave Posted April 9, 2009 Report Share Posted April 9, 2009 i have not experienced this with any of my scopes,but have heard that this used to be fairly common on cheeper scopes,if your scope suffers with ths problem either send it back to the manufacturer or upgrade :blink: Quote Link to comment Share on other sites More sharing options...
fullbore Posted April 9, 2009 Report Share Posted April 9, 2009 The POI moves as you adjust the mag Really? what's the point of that then? Quote Link to comment Share on other sites More sharing options...
markbivvy Posted April 9, 2009 Report Share Posted April 9, 2009 The POI moves as you adjust the mag if it does , bin it. Quote Link to comment Share on other sites More sharing options...
wildfowler.250 Posted April 9, 2009 Author Report Share Posted April 9, 2009 Yeah dont see the point in that may have to send it back by the sounds of it ? :blink: Quote Link to comment Share on other sites More sharing options...
chrisv Posted April 9, 2009 Report Share Posted April 9, 2009 You need to set out several targets and shoot them on different mags, if the POI changes significantly, then follow Mark's advice Quote Link to comment Share on other sites More sharing options...
garyb Posted April 9, 2009 Report Share Posted April 9, 2009 We've been here before 100's of times.... I remember Pin offering a detailed technical explanation as to why the last time around From real world use, on both my rifles and others - I've seen this 1st hand many a time, just the other week I missed 3 bunnies in a row with Stealth Stalker at the lamp... When I checked my scope I had left it at 20x after trying to I.D a fox - changed it back to 8x - dead rabbits again. Mine are always left fixed on 8x. Quote Link to comment Share on other sites More sharing options...
markbivvy Posted April 9, 2009 Report Share Posted April 9, 2009 Not sure if i have seen pins account of this. but for my money any POI change due to changing the mag would either be , shooter error or parallax error. only ever had 1 scope that did it, and it went back, the replacement was fine. 20 mag can throw up a fair bit of wobble. Quote Link to comment Share on other sites More sharing options...
Blackbart Posted April 9, 2009 Report Share Posted April 9, 2009 The POI moves as you adjust the mag It does move.I dont know the tech reason why but it deffo changes your poi,especially if you move from say 6 to 18 or any other big jump Quote Link to comment Share on other sites More sharing options...
Harnser Posted April 9, 2009 Report Share Posted April 9, 2009 Has the scope been zeroed on max magnification ? if not try it that way . Harnser . Quote Link to comment Share on other sites More sharing options...
markbivvy Posted April 9, 2009 Report Share Posted April 9, 2009 just found this. http://www.eabco.com/Reports/report01.html this is the interesting bit. ADJUSTMENT CONSISTENCY It stands to reason that if your scope reticle doesn’t stay at the same point of adjustment, it will not give you the same point of aim from one shot to the next. Scopes adjust the reticle by screws which push the reticle tube against a spring. From one shot to the next, recoil might shift the reticle tube against the spring. As long as it returns to the same position, the scope will keep the same point of aim. But if it moves, your scope will not shoot accurately. A good scope will have little or no movement of the reticle tube and adjustments will stay consistent regardless of recoil. Sometimes the point of impact can change simply by zooming the magni-fication on a variable power scope. How-ever, this situation doesn't happen much in the scopes we have now-a-days Quote Link to comment Share on other sites More sharing options...
pin Posted April 9, 2009 Report Share Posted April 9, 2009 Depends on the scope, and how its made. If it's cheap the POI will move with the magnification, if its really cheap it won't be back at the same place when it's back at the same magnification as the zero. Quote Link to comment Share on other sites More sharing options...
harv Posted April 9, 2009 Report Share Posted April 9, 2009 what type of scope is it? it is probably down to the build quality and as mr bivvy has stated the tension screws and springs must be cock on if going to very high mags. i would also check for parallax error by securing the rifle and without touching it look at a target at 100 yds thru the scope the move your head to either side and up and down and see if the crosshairs move off the target, the more it moves the higher the error. you can find the point of parallax free by setting up at various distances and seeing where the reticle stays bang on. Quote Link to comment Share on other sites More sharing options...
pin Posted April 9, 2009 Report Share Posted April 9, 2009 Fair points, and all valid... If you can group well with the zero'd magnification, consistently, from different positions (ie not get comfy and do 30 shots from prone) - then it's fair to assume that your head, and therefore your eye is coming back to the same place, and therefore your eye is in the same place. Parallax will come in to it, as rightly said, for example if you zero at 4x and try the same thing at 20x - your error will be, pardon the pun, magnified, considerably. Quote Link to comment Share on other sites More sharing options...
wildfowler.250 Posted April 9, 2009 Author Report Share Posted April 9, 2009 Thanks very much Its a leupold scope btw so don't know what category that falls into? now just to go out and try and make sense of this parralax Quote Link to comment Share on other sites More sharing options...
macca Posted April 9, 2009 Report Share Posted April 9, 2009 Hi, Ive seen a leupold on our target range shoot an inch and a half difference in POI from 6 power to 20 power. It went back to Leupold to be fixed - came back the same - went back for a refund. Find a place where you can bench the gun (front and back bags) set your target at 50 metres. Set you front paralex correctly. Shoot 3 shots at 8 power then 3 at your high power. Good scopes will give you one group. Ifyou have two groups youve got a problem. The scope on my main gun for the culling work I do is an old 8x56 Khales - no POI problems. Simple is best. Cheers Quote Link to comment Share on other sites More sharing options...
realtreedave Posted April 9, 2009 Report Share Posted April 9, 2009 for the money that a leopold scope costs this isnt a problem caused through buying cheep,i wouldnt expect this problem on scopes costing a fraction of leopold,s prices.thissounds like a genuine fault send it back or get your money back.this type of fault is simptomatic of cheep ,often oriental manufacture,that seems to have almost dissapeared from modern scopes wherever their origin.beware though some of these big brand american scopes are not too truthfull of their origins,and you may be paying the price for this Quote Link to comment Share on other sites More sharing options...
pin Posted April 9, 2009 Report Share Posted April 9, 2009 Just playing devils whatsit... Just because it's a leo (you don't say which or how old or what life it's had) doesn't make it a sure thing... As most would say, it's not usual for a quality make like leo to behave like this. If you can consistently move from one group to another, and back, rested, at different mags, I'd be worried. If you can't, I'd be more worried. If you can repeat groups at the same POI, at different mags, that pretty much rules out mounts, creep, well, just about everything apart from the scope or you, the only reliable way to take yourself out of the equation is repeat off a rest, ignoring POI compared to you shooting it (assuming you can be sure the rifle still shoots well in a mount, ie not clamping it too hard, twisting it so it affects harmonics etc).. Quote Link to comment Share on other sites More sharing options...
njc110381 Posted April 9, 2009 Report Share Posted April 9, 2009 If I had that kind of trouble from my Leupold it would go back. That's not acceptable from a scope of that price and quality. Quote Link to comment Share on other sites More sharing options...
realtreedave Posted April 9, 2009 Report Share Posted April 9, 2009 it cant be paralex error if the results are consistent,paralex error works on the scope not being set up for your eye/head position/eyes focus,so te results would be inconsistent,if the results are consistent then the problem is mechanical ie the scopes internals Quote Link to comment Share on other sites More sharing options...
pin Posted April 9, 2009 Report Share Posted April 9, 2009 (edited) Normally your right, I'm not saying you are wrong.... If we were talking about 5 shot groups, change mag then 5 more, rested on a range - I'd agree... If we are talking about a nights shooting, however comprised, changing mag at the same time as changing mount, makes more difference than people will admit. Parallax is all about accuracy of the line of sight of the eye. If you line up perfectly behind the scope every time, no problem. If you tend to have a slightly different head position due to shooting out of a truck, off a gate post or whatever - parallax is the ERROR you induce compared to when you zero'd - nothing more. The distance of the object you are shooting at is inversely proportional to the parallax error, ie the further you are away - say double, you basically multiply the parallax error by two. Edited April 9, 2009 by pin Quote Link to comment Share on other sites More sharing options...
realtreedave Posted April 9, 2009 Report Share Posted April 9, 2009 Normally your right, I'm not saying you are wrong.... If we were talking about 5 shot groups, change mag then 5 more, rested on a range - I'd agree... If we are talking about a nights shooting, however comprised, changing mag at the same time as changing mount, makes more difference than people will admit. Parallax is all about accuracy of the line of sight of the eye. If you line up perfectly behind the scope every time, no problem. If you tend to have a slightly different head position due to shooting out of a truck, off a gate post or whatever - parallax is the ERROR you induce compared to when you zero'd - nothing more. The distance of the object you are shooting at is inversely proportional to the parallax error, ie the further you are away - say double, you basically multiply the parallax error by two. quite agree, but paralex error and point of impact moving through changing magnification are quite distinctly dfferent,although easily confused.your head is easily moved so can adjust eye relief,your eye is an automatic focusing optic,the reticule is adjustable for eye relief and the objective is either fixed or adjustable ,there is a lot of room to find the happy medium here,and an error would either be miniscule or glaringly obvious.zoom error would not put the reticule out of focus nor the target[presuming paralex adjustable scope] Quote Link to comment Share on other sites More sharing options...
pin Posted April 10, 2009 Report Share Posted April 10, 2009 quite agree, but paralex error and point of impact moving through changing magnification are quite distinctly dfferent,although easily confused.your head is easily moved so can adjust eye relief,your eye is an automatic focusing optic,the reticule is adjustable for eye relief and the objective is either fixed or adjustable ,there is a lot of room to find the happy medium here,and an error would either be miniscule or glaringly obvious.zoom error would not put the reticule out of focus nor the target[presuming paralex adjustable scope] Point taken. Nobody said focus... I simply said, if you zoom 20x and move your head, you'll miss. If you zoom 4x and move the same, your a lot less likely to miss. Quote Link to comment Share on other sites More sharing options...
Blackbart Posted April 10, 2009 Report Share Posted April 10, 2009 I agree pin...small jumps do not matter but go from 4 to 20 and i have problems. It doesnt make a difference on something 60 yards away but the small difference it makes matters when your target is 200 yards away. Quote Link to comment Share on other sites More sharing options...
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