Thread: Scope alignment methods

Originally Posted by zimmer

+1 The only correct method to set up a scope. Centres the scope vertival retical thru bore centre. Most other methods are good enough though for hunting rifles. Dialling up at long range will show up inaccuracies of mounting.

I too made one but eventually bought the Brownells version.

Once the scope is mounted I've also gone to bore sighting using a strong torch thru the ocular lens projected onto a plumb bob string line. With this method I can bore sight very accurately in the length of my gun room. I can also do the vertical travel check, winding the cross hair up and down the string.

This method @PaulNZ looks interesting - I'm not quite following how it works?

Originally Posted by blip

I set rifle up on bipod or gun vice put up a mirror and look through scope mounted on rifle at mirror. Compliment yourself on how good looking you are. Then just get the bottom portion of cross hair to run through center of barrel.

Interesting - I'll have to give it a try and see how close I am.

Also optically centre the scope before starting to mount using either the mirror method or count clicks fully one way to the other then come back half way.
If once the scope is mounted you have to use excessive windage clicks to zero your shots there is something wrong with the geometry, one reason being poor quality rings.
It is undesirable to have the scope at windage extremes. Scopes are optically best when their reticles are as close to centre as possible.

Correcting excessive windage also may need windage adjustable rings.
Some rifles are shockers. I've put spirit levels on the back section of the dovetail and it doesn't match a spirit level on the front section of the dovetail. And that was on a name brand of rifle. Likewise fitted rails - spirit level front to back doesn't match. Bushed rings are very forgiving.

I draw a line down the center of an A4 piece of paper, sit the rifle on the line - aligned down the center of the butt and enough of the line sticking out you can see it through the scope. Look down the scope from the barrel end and align with the line.

Originally Posted by vulcannz

I draw a line down the center of an A4 piece of paper, sit the rifle on the line - aligned down the center of the butt and enough of the line sticking out you can see it through the scope. Look down the scope from the barrel end and align with the line.

That sounds far too simple ��

Originally Posted by earplay

That sounds far too simple ��

Yep, but it works. Don't overthink it, guys!

Yep. Getting the thing mounted to the rifle is but one component.

Shooting it tells you if it's good - what really screws with your head is discovering your expensive new toy as a glass etched (round) reticle and that the round glass isn't in line with your threads.

It's OK winding it up and down with a line right in front of you but you need to get out to leg-stretch distance and wind the full turns up and see which side the round land on the line to know if the scope's adjustment threads are level to the reticle.

I've had a brand new Leupold 45degs on the piss (like the reticle is going to four corners not up and down literally) and that went back, and extreme case but the errors are out there!

I hang my plumbulb from my white tail antlers down the other end my 8.6mtr long lounge.He dont mind and a plum bulb can only hang true plum from a thin peice of string.

Originally Posted by earplay

This method @PaulNZ looks interesting - I'm not quite following how it works?

The small vee on the long piece of the jig is placed on the barrel just in front of the scope objective - being a vee it self-centres. Loosen the lock nut and bring the larger vee down to contact the outside of the scope objective. Now your jig is located exactly on the line between barrel centre and the scope centre. This line is probably not true vertical (yet), so move the rifle on whatever rest or clamp you're using until the bubble is centred. Your scope/rifle assembly is now true vertical, so you can rotate the scope (without moving the rifle) until the crosshairs match another true vertical reference - like a plumb bob.

If your question is instead about bore sighting with a torch through the ocular lens, I'll leave @zimmer to explain that one further. Sounds like something I need to try though.

Originally Posted by PaulNZ

The small vee on the long piece of the jig is placed on the barrel just in front of the scope objective - being a vee it self-centres. Loosen the lock nut and bring the larger vee down to contact the outside of the scope objective. Now your jig is located exactly on the line between barrel centre and the scope centre. This line is probably not true vertical (yet), so move the rifle on whatever rest or clamp you're using until the bubble is centred. Your scope/rifle assembly is now true vertical, so you can rotate the scope (without moving the rifle) until the crosshairs match another true vertical reference - like a plumb bob.

If your question is instead about bore sighting with a torch through the ocular lens, I'll leave @zimmer to explain that one further. Sounds like something I need to try though.

Ok I think I get, cheers. Some great knowledge on the forum, and few new ideas try!