R33SY Posted December 31, 2014 Report Share Posted December 31, 2014 Hi all I know this is often asked and I have read most topics on how to zero a scope what I hope you can help me with is trying to understand my thinking behind my attempts I have a BSA R10 Mk2 I have just replaced the scope with a hawke 4-12 x 50 ao I also replaced the regulator with an xtx one I reset both elevation and windage to the central positions set up a target at 25 yards and took a shot , the shot was 6" high and 6" to the right (not what I was expecting ) I took a few more shots and all were consistent around that area I was hoping to only have to adjust the scope maybe 20 or 30 clicks but 6" at 25 yards works out at about 96 clicks Now I am an engineer by trade and things like this bug the hell out of me so I designed some custom mounts on my cad system that I could machine at work on one of our 5 axis cnc mills with very tight tolerance just in case these shop bought ones were not very good I made some that were perfectly straight and inline and I made a pair that were on the skew to the right by about .025" thou I put my straight home made ones on retried and still placed the pellet in the same place, so shop bought ones are pretty good for the money ! I put my custom angled ones on and he presto I am about half an inch out on the vertical line still shooting high though so I may make some more with a double offset (to the right and upwards ) Is it normal to have to adjust sights by this amount ? and I would have of expected to shoot lower looking through the scope as it is mounted higher Or have I got all my thinking wrong ? Thanks for Looking R33SY Quote Link to comment Share on other sites More sharing options...
1066 Posted December 31, 2014 Report Share Posted December 31, 2014 Yes, you're right, 6" out at 25yds is a long way off, that's about 24moa and more than most scope would be able to adjust anyway. There is obviously something out of line a little, and on an R10 I would guess it's the barrel. As an engineer you will appreciate the leverage of a couple of feet of pipe held in place by just the last two inches, it only requires a careless knock with a free floating barrel to move it a few thou. As you're obviously someone who is willing to experiment, I would try reversing one of your shop bought mounts and try again, it cost nothing and might give you more data. Is the scope known to be good? Have you got another to try? If the barrel is out of line, playing around with altering the mounts won't cure the problem, you may well get it to shoot to point of impact at 25 yards but as you extend the range the error will creep back in. Here's a short video I made on how to quickly zero a scope - it might help. Quote Link to comment Share on other sites More sharing options...
R33SY Posted December 31, 2014 Author Report Share Posted December 31, 2014 Thanks for replying I agree with you something has to be off somewhere and the barrel would seem to be the likely culprit I realise I have got the gun to shoot at poa at 25 yards but the error will still be there further out I did try with another scope I own and its pretty much the same results I haven't dropped or banged the barrel that I am aware of so not sure what could have happened the error equates to about a 1/4 of a degree over 25 yards not much really but still enough to bug me I did try reversing the mounts but no real change as the dovetail is pretty central I did think it was maybe due to me changing the regulator I have not chronoed it yet so could be under powered at the moment it is ok for plinking Regards R££SY Quote Link to comment Share on other sites More sharing options...
1066 Posted December 31, 2014 Report Share Posted December 31, 2014 Have you got a moderator on? If so try it without. I think it would be unlikely to be a problem with the regulator. I think you would notice if it was drastically down on power, say less than 7ftlbs and at even low power they should go reasonably straight at 25 yards. Are they pellets that you've had good results with that rifle before? Has the crown had a ding? If all else fails. give it a clean Quote Link to comment Share on other sites More sharing options...
R33SY Posted December 31, 2014 Author Report Share Posted December 31, 2014 The moderator is of my own design and making its not clipping and I've not had chance to try it without as my neighbours Are of the type to call the law at the first sound of a muzzle crack The pellets I was given and are AA fields my preferred ammo is Accupels so that is something I could try Cleaning I hadn't thought about that so that is defiantly on the books to do As for power I too don't think it's down I use an internal door for my backstop with carpet behind it to arrest the pellet and at 25 yards its passing cleanly through the door Roughly how far are most people out with there first shot when setting up a scope ? Thanks for your help tand ideas to try Best regards R33SY Quote Link to comment Share on other sites More sharing options...
subsonicnat Posted December 31, 2014 Report Share Posted December 31, 2014 Try sighting through the Barrel then look through the scope at 25 yds it would be a mile out.. Have slipped a bit of camera film in one that was giving problems, but when all said and done, not that far out.. Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 1, 2015 Report Share Posted January 1, 2015 If your mounts are dead true and your scope is centered adjustment wise and your pellet is going 6" inches wide at 25 yards then your barrel is out of alignment or bent-simple as. Making off-set mounts will only help at the range you set your zero at. Quote Link to comment Share on other sites More sharing options...
evo Posted January 1, 2015 Report Share Posted January 1, 2015 the BSA R10 mk2 I had was also out,,by about 1/2mm at 40yrds so you defo have something seriously wrong somewhere :lol: a super accurate gun and one which I was sorry I got shut of hope you get it sorted but sorry to inform you but even being underpowered would not cause it to be that far out at 25yrds so I have to agree with Bruno22rf again as usual lol atb Evo Quote Link to comment Share on other sites More sharing options...
R33SY Posted January 1, 2015 Author Report Share Posted January 1, 2015 Thanks for all your replies it certainly gave me something to think about My gun shoots off by 6' inches at 25 yards doing the maths with trig that's about a quarter of a degree not a bad tolerance for a mas s produced gun My scope is now aligned on the same angle as the trajectory of the pellet so different distances should not make a difference If I had used mounts that were straight and adjusted the scope in the usual way then I think I would have problems at differing ranges due to the misalignment of scope and barrel Well that's my theory behind it but like a lot of times my theory and practice don't always work out Though I am having a lot of fun learning along the way Happy new year to PW Members and thanks for taking the time too look in and comment R33SY Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 1, 2015 Report Share Posted January 1, 2015 Test your theory-if you shoot and zero at ,say, 30 yards-try 15 and then 45 yards-does the pellet strike different sides of the target? The R10 seems to suffer from the odd build quality issue-I seem to remember that Gamo made some of the barrels and the machining quality was poor-if the barrel is not square in the action you are fighting a losing battle-do you know any engineers that could run a Dial Indicator clock along the action/barrel. Quote Link to comment Share on other sites More sharing options...
1066 Posted January 1, 2015 Report Share Posted January 1, 2015 (edited) Test your theory-if you shoot and zero at ,say, 30 yards-try 15 and then 45 yards-does the pellet strike different sides of the target? The R10 seems to suffer from the odd build quality issue-I seem to remember that Gamo made some of the barrels and the machining quality was poor-if the barrel is not square in the action you are fighting a losing battle-do you know any engineers that could run a Dial Indicator clock along the action/barrel. If you read the first post I think this chap's got the ability to do just that - also to remove the barrel and press it back into line or even chop off three inches at the breech end and re-machine it true. (this is the way I would go) Off setting a scope to get you out of a fix might work but, Mr. R33SY, the engineer in you knows there's a better solution:) Edited January 1, 2015 by 1066 Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 1, 2015 Report Share Posted January 1, 2015 (edited) To be honest I'm surprised that the OP did not check alignment with a dial gauge (or even a steel rule and slips) before going to the considerable effort of making a set of mounts 1/2 mm off center-no offence meant but it would take minutes to check. Edited January 1, 2015 by bruno22rf Quote Link to comment Share on other sites More sharing options...
R33SY Posted January 1, 2015 Author Report Share Posted January 1, 2015 (edited) Hi all and thanks for your ideas I shall remove scope ,silencer and stock tomorrow clan barrel mount in a fixture and see how it shoots Before reassembling silencer first then scope to see if any changes occur it will give me something to do Checking alignment would be easy at work but not back in till the 5th Whilst in bits I will recrown the barrel as well I don't mind making bits for it. It sort of personalises my gun Anything I make that's good usually gets made in numbers and sold Carbon shrouds silencers in carbon and ally etc The r10 is a good looking gun but was built to a price and some parts are disappointing on it from a quality point of view But in all fairness on the whole it does do what it is supposed too I do have a nice straight edge suitable for checking barrel to reciever alignment and that will be interesting Without your inputs I wouldn't of thought of a lot of things to check I seem to be in holiday mode and need to get my brain in gear Hopefully I can get some photos up of it and the bits I have made for your comments Thanks again R33SY Oh and 1066 you are so right at the moment I have a solution to a problem but have not actually fixed the problem itself ! Edited January 1, 2015 by R33SY Quote Link to comment Share on other sites More sharing options...
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