I have been using a boresighter to get me on paper for many, many years without any problems except for my last experience.
I have a TC Pro Hunter in 300 WM with a 28" barrel and before using it to go moose hunting, I adjusted a new scope for it (Bushnell 3200 4-12X40 with DOA) using a Bushnell professional model boresighter.... something that I have done every year since the 80's. This time when I took some shots at an official target for final sighting, I was off paper and had no ideal where I was. After playing around, I was able to sight the rifle within an inch of the intended spot and repeated that for around 6 shots.
When I got home, I rechecked the scope with the boresighter and found that the scope cross hair in the vertical direction (horizontal line) was approx 14" high. but right on for windage. Reference material since obtained mentions that I should remember these numbers for future reference as this happens from time to time.
Further investigation revealed that my rings are higher than what I'm used to to the extent that the centre line of the scope is approx 2" above the centre line of the bore and that the centre line of the boresighter is only approximately 1.5" higher than that same centre line.
A quick trigonometric evaluation of the situation supported the assumption that a situation like that would generally lead to what I have (same direction). To my somewhat disappointment, I have not been able to come up with numbers that would give me a basically 14" shift at 100 yd.
For curiosity sake, I'm wondering if anyone here has run against this problem and what their experience has been.
My experience with the Bushnell boresighter has been excellent and a tool I would not do without.
Thanks for any input you might have,
Duke1
I have a TC Pro Hunter in 300 WM with a 28" barrel and before using it to go moose hunting, I adjusted a new scope for it (Bushnell 3200 4-12X40 with DOA) using a Bushnell professional model boresighter.... something that I have done every year since the 80's. This time when I took some shots at an official target for final sighting, I was off paper and had no ideal where I was. After playing around, I was able to sight the rifle within an inch of the intended spot and repeated that for around 6 shots.
When I got home, I rechecked the scope with the boresighter and found that the scope cross hair in the vertical direction (horizontal line) was approx 14" high. but right on for windage. Reference material since obtained mentions that I should remember these numbers for future reference as this happens from time to time.
Further investigation revealed that my rings are higher than what I'm used to to the extent that the centre line of the scope is approx 2" above the centre line of the bore and that the centre line of the boresighter is only approximately 1.5" higher than that same centre line.
A quick trigonometric evaluation of the situation supported the assumption that a situation like that would generally lead to what I have (same direction). To my somewhat disappointment, I have not been able to come up with numbers that would give me a basically 14" shift at 100 yd.
For curiosity sake, I'm wondering if anyone here has run against this problem and what their experience has been.
My experience with the Bushnell boresighter has been excellent and a tool I would not do without.
Thanks for any input you might have,
Duke1
