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Zeroing a 17hmr at 25 yards for 100 zero
Posted: Sun Aug 21, 2022 9:55 pm
by shotgun sam
If zeroing a 17hmr on a 25 yards range what is the hold over so that the zero is perfect for 100 yards
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Mon Aug 22, 2022 1:38 am
by 1066
Should be able to work it out with "Strelok" or other ballistic app if you know the velocity and scope height.
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Mon Aug 22, 2022 7:18 am
by Blackstuff
Its impossible to know without all of the details of the rifle, bullet and cartridge. When I had a .17HMR I zeroed it at 100 and never had to do anything but point and shoot from 30-130m
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Mon Aug 22, 2022 11:37 am
by Pippin89
As above the free version of Strelok will work it out for you. You can even find your reticle and see the aim point I believe.
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Tue Aug 23, 2022 6:21 pm
by Graham M
Not really applicable because the slightest amount of cant at 25yds will cause the bullet to miss at 100yds so you would be better off just sighting in a 100yds to start with.
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Tue Aug 23, 2022 10:20 pm
by 1066
Graham M wrote: ↑Tue Aug 23, 2022 6:21 pm
Not really applicable because the slightest amount of cant at 25yds will cause the bullet to miss at 100yds so you would be better off just sighting in a 100yds to start with.
Surely this is how the zero cards work on the 71'7" range at Bisley. If you have the right card for your ammunition you can set your sights for anything up to a thousand yards .
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Wed Aug 24, 2022 6:22 am
by Ovenpaa
Yup, you are spot on 1066
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Wed Aug 24, 2022 10:02 am
by Graham M
Theoretically yes. But you only need to have 5 degrees of left cant on the rifle and you could be 12 inches to the left at 100yards
I shoot with around 25 degrees of cant with my .22 match rifle so when I go from 25yds to 50 metres (yeh I know bloody international distance) I have to go up one and a half minutes and across to the right one minute. Going up to 100yds I have to go up another seven minutes and then another, almost two minutes, to the right windage. So from 25yds to 100yds I am winding on almost three minutes of windage otherwise I would be on the edge of the target and low.
If you are shooting off a bipod and the rifle is perfectly upright then I suppose it's OK. but for sighting a 17Hmr in at 100 yds it's much simpler to just sight it in at 100yds.
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Wed Aug 24, 2022 11:16 am
by 1066
shotgun sam wrote: ↑Sun Aug 21, 2022 9:55 pm
If zeroing a 17hmr on a 25 yards range what is the hold over so that the zero is perfect for 100 yards
You want some hold under Sam.
Making some assumptions here. Velocity 2650fps, Bullet weight 17gn, Bullet BC .115, Scope height above bore 1.97"
At 25yds the point of impact will be .87 inches
below your aim point.. The bullet will remain below your aim point until it gets to 55yds.. It rises to a maximum of .16" above aim point at 85yds and drops back to zero at 100yds. From 50-100yds there's only 1/4" either way.
Re: Zeroing a 17hmr at 25 yards for 100 zero
Posted: Wed Aug 24, 2022 11:26 am
by 1066
Graham M wrote: ↑Wed Aug 24, 2022 10:02 am
Theoretically yes. But you only need to have 5 degrees of left cant on the rifle and you could be 12 inches to the left at 100yards
I shoot with around 25 degrees of cant with my .22 match rifle so when I go from 25yds to 50 metres (yeh I know bloody international distance) I have to go up one and a half minutes and across to the right one minute. Going up to 100yds I have to go up another seven minutes and then another, almost two minutes, to the right windage. So from 25yds to 100yds I am winding on almost three minutes of windage otherwise I would be on the edge of the target and low.
If you are shooting off a bipod and the rifle is perfectly upright then I suppose it's OK. but for sighting a 17Hmr in at 100 yds it's much simpler to just sight it in at 100yds.
I understand what you are saying Graham, although it does seem to me, with all the myriad of adjustments available on the modern match rifle there's a serious design fault if the sights can't be rotated to stay vertical no matter what cant you prefer - Maybe they do on modern modular match rifle, I'm well out of touch with cutting edge match rifles.