Rifle sighting question

Moderators: pilkguns, Marcus, m1963, David Levene, Spencer

Post Reply
lyoke
Posts: 55
Joined: Mon Jul 20, 2015 7:33 am

Rifle sighting question

Post by lyoke »

I have Anschutz 7020 sights. I put on a new tube and resighted my rifle. My group was quite high. 5 Inches or so above the bull at 50 meters. I clicked my sights down quite a bit to get to the center of the bull but I have found that my sights do not have much room left to go down much further. Do I need to raise my rear sight to lower my group so I can adjust my sights back up or do I need to raise my front sight to achieve this?

Thank you.
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Rifle sighting question

Post by Tim S »

You need to raise the foresight to point the muzzle down. A block just under the rearsight will make matters worse, as this will point the muzzle even higher.
Rover
Posts: 6986
Joined: Sat Nov 15, 2008 4:20 pm
Location: Idaho panhandle

Re: Rifle sighting question

Post by Rover »

It's easy if you remember to move the rear sight in the direction you want the shot to go.
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Rifle sighting question

Post by Tim S »

Rover wrote:It's easy if you remember to move the rear sight in the direction you want the shot to go.
Doesn't help much when it's bottoming out. lift the foresight instead. The OP has fitted a sight extension tube; the extra length and maybe tube diameter vs muzzle dia have effectively lowered the foresight.
Rover
Posts: 6986
Joined: Sat Nov 15, 2008 4:20 pm
Location: Idaho panhandle

Re: Rifle sighting question

Post by Rover »

Gee, do you think he might have figured that out?
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Rifle sighting question

Post by Tim S »

Rover wrote:Gee, do you think he might have figured that out?
Duh, no. Otherwise he wouldn't have asked if he needed a rearsight raiser.

He had successfully re-zeroed, but wanted to free some elevation.
Rover
Posts: 6986
Joined: Sat Nov 15, 2008 4:20 pm
Location: Idaho panhandle

Re: Rifle sighting question

Post by Rover »

How silly of me to have considered such a thing.
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Rifle sighting question

Post by Tim S »

Rover wrote:How silly of me to have considered such a thing.
Well, if the cap fits.

Lyoke,

apologies for hijacking your thread. If your sightline was a comfortable height before switching tubes, try a 4mm block under the foresight tunnel. That should put you back roughly to where you were before. If you can't find a 4mm to fit, you could use an 8mm block, but might need a 4mm block under the rearsight. This will raise the whole sightline, and you need to raise the cheekpiece and probably the buttplate too (if a hook type).
lyoke
Posts: 55
Joined: Mon Jul 20, 2015 7:33 am

Re: Rifle sighting question

Post by lyoke »

Thanks guys! I have an extra 4mm block that I will put under the front sight. I think that will help with my issue.

I appreciate the advice as always.
GaryD
Posts: 133
Joined: Sat Aug 13, 2011 2:14 pm
Location: Wales, UK

Re: Rifle sighting question

Post by GaryD »

lyoke wrote:Thanks guys! I have an extra 4mm block that I will put under the front sight. I think that will help with my issue.

I appreciate the advice as always.
Try the 4mm block under the front sight especially as you have one, but in my opinion it will be too much as I reduced the height
of my foresight by 1mm and the point of impact moved about 3 inches.

Please let us know what happens.
TenMetrePeter
Posts: 603
Joined: Sun Sep 04, 2016 10:59 am

Re: Rifle sighting question

Post by TenMetrePeter »

Using simple similar triangles concept a 1mm sight drop will give 50/L mm at the 50 metre target where L is the sight radius in metres.

3 inches for 1mm change with a radius less than a metre is spot on.

So...
1 metre sight radius with 4mm riser block on foresight will drop 200mm (8 inches) at 50 metres.

All approximately of course!
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Rifle sighting question

Post by Tim S »

I'd figured the foresight needed to go up by 2.5mm, so a 4mm block would be the closest and simplest. However, if the whole sightline can go up, a set of adjustable raisers would be best.
GaryD
Posts: 133
Joined: Sat Aug 13, 2011 2:14 pm
Location: Wales, UK

Re: Rifle sighting question

Post by GaryD »

TenMetrePeter wrote:Using simple similar triangles concept a 1mm sight drop will give 50/L mm at the 50 metre target where L is the sight radius in metres.

3 inches for 1mm change with a radius less than a metre is spot on.

So...
1 metre sight radius with 4mm riser block on foresight will drop 200mm (8 inches) at 50 metres.

All approximately of course!
As you say Peter it is all approximate, I found that at the end of the day experimenting was best for me.

Before I went to the range I would file the bottom of the front sight carefully a bit at a time until the rear sight had plenty of movement, both up and down.
GaryD
Posts: 133
Joined: Sat Aug 13, 2011 2:14 pm
Location: Wales, UK

Re: Rifle sighting question

Post by GaryD »

Tim S wrote:I'd figured the foresight needed to go up by 2.5mm, so a 4mm block would be the closest and simplest. However, if the whole sightline can go up, a set of adjustable raisers would be best.
I also tried adjustable raisers as well, but I personally was not happy with having to raise my cheek piece up so high.

But there again its down to personal preference.

Its now time to go and pack as I am off to Bisley for a week, for some frustration but hopefully good weather.
Post Reply