Like the attached picture, I am thinking of adjust my rear sight higher than the front sight. I wonder if this causes any defect or problems in
shooting 10m air rifle.
Also, I want to know why both rear and front sight must be at the same height. Is there any 10m air rifle player who has set those two at different height?
Thanks in advance.
Can rear sight height be higher than front sight?
Moderators: pilkguns, Marcus, m1963, David Levene, Spencer
Can rear sight height be higher than front sight?
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A direct answer to your question is Yes.
As a matter of fact ,as the distance of both front and rear sights increases from the barrel axis(sight risers)the greater the difference between the two will be(sorry for my English)
You may insert the same height sight risers,but the peep sight of the rear iris will go higher in order to bring the projectile to the aiming point.
The result will be a rear iris clicked higher form the center of the rear sight,which of course is not a problem for ten and fifty meter shooting,but is a problem at high power rifle.
In my case,for my air rifle and my standing position,I use the max of permitted sight risers plus for mm extra at the rear sight(to get the iris at the center of the rear sight,but hey, it's just me and it works without the extra 4mm)
I hope you understood me!
As a matter of fact ,as the distance of both front and rear sights increases from the barrel axis(sight risers)the greater the difference between the two will be(sorry for my English)
You may insert the same height sight risers,but the peep sight of the rear iris will go higher in order to bring the projectile to the aiming point.
The result will be a rear iris clicked higher form the center of the rear sight,which of course is not a problem for ten and fifty meter shooting,but is a problem at high power rifle.
In my case,for my air rifle and my standing position,I use the max of permitted sight risers plus for mm extra at the rear sight(to get the iris at the center of the rear sight,but hey, it's just me and it works without the extra 4mm)
I hope you understood me!
Think of it like this:
If you want to raise the rearsight, you must also raise the foresight proportionately.
When you alter your sights - what you are REALLY doing is altering the angle of the rifle - the sightline (eye > rearsight > foresight > target) should always be the same for a perfect aim.
So by making the rifle point higher or lower, you get a point of impact at the target that is higher or lower.
If you want to raise the rearsight, you must also raise the foresight proportionately.
When you alter your sights - what you are REALLY doing is altering the angle of the rifle - the sightline (eye > rearsight > foresight > target) should always be the same for a perfect aim.
So by making the rifle point higher or lower, you get a point of impact at the target that is higher or lower.
thanks for your replies
all helped a lot. thanks!
For 10m air rifle you can use max. 60 mm (ISSF Rule) for your front sight, measured from the middle of the barrel to the middle of the front sight. Then you have 60 mm + x on the rear sight, because the rear sight is always a little bit higher then the front sight, as explained in the last postings. To hit a target on certain distance you need always a definite relationship between the front and rear sight.
The projectile on earth goes always a ballistic path to the ground. So, if you have the sights parallel to the barrel, the projectile wont never hit your aiming point.
In the picture from KennyB you can see the sightline hit the ballistic path at two points. For airguns often the rear sight is adjusted to the first point from the barrel and for other guns to the second point. So if you go nearer to the target with your airgun, the hits will drop.
For 50 m smallbore (ISSF) there is no limit for the sights.
Best wishes from Germany and excuse my bad English
Frank
The projectile on earth goes always a ballistic path to the ground. So, if you have the sights parallel to the barrel, the projectile wont never hit your aiming point.
In the picture from KennyB you can see the sightline hit the ballistic path at two points. For airguns often the rear sight is adjusted to the first point from the barrel and for other guns to the second point. So if you go nearer to the target with your airgun, the hits will drop.
For 50 m smallbore (ISSF) there is no limit for the sights.
Best wishes from Germany and excuse my bad English
Frank
Assuming constant velocity of 175 meters per second from the muzzle to the target (no deceleration due to air drag) I get a flight time of 0.057 seconds and a drop due to gravity of about 16mm. My bore centerline to front sight centerline is about 40mm so in reality the relations and angles must be set up to overcome the 40mm centerline difference plus an additional 16mm gravity drop.
Assume 10m from front sight to target and 0.8m sight radius and I get a rough estimate the rear sight will need to be about 4.5mm above the front sight. Due to the assumption of constant velocity the drop due to gravity is underestimated so it will need to be a bit more but this is a decent first order estimate.
Bottom line, you cannot arbitrarily move the rear sight without also moving the front sight. The front and rear sight must be in a pretty specfic relationship to one another if you expect to shoot tens.
'Dude
Assume 10m from front sight to target and 0.8m sight radius and I get a rough estimate the rear sight will need to be about 4.5mm above the front sight. Due to the assumption of constant velocity the drop due to gravity is underestimated so it will need to be a bit more but this is a decent first order estimate.
Bottom line, you cannot arbitrarily move the rear sight without also moving the front sight. The front and rear sight must be in a pretty specfic relationship to one another if you expect to shoot tens.
'Dude