Bore/Scope collimators

[Northwest]

As bullets are becoming harder to find I am no longer quite as keen to throw half a dozen rounds downrange to sight my rifles in so I am looking at buying a bore collimator.
Specifically I have been looking at this one made by Bushnell:

Does anyone have any experience of them?

 

[User00040]

As bullets are becoming harder to find I am no longer quite as keen to throw half a dozen rounds downrange to sight my rifles in so I am looking at buying a bore collimator.
Specifically I have been looking at this one made by Bushnell:

Does anyone have any experience of them?

Yes:

Bushnell Professional Boresighter, a quickfire review

Hi all, With the impending ammo/reloading component famine I decided to try the following product, the Bushnell Professional Boresighter. Regrettably, I paid the eye-water Amazon price of just under £140 delivered. However, they were the only source that I could find that would ship to me...

www.thestalkingdirectory.co.uk

Use mine often.

Handy for levelling scopes, checking zero, scope tracking and holding zero across magnification range.

Make sure you get the kit with adjustable augers as the ones that come with loads of fixed ones or worse still the mganetic version, don't work so well.

 

[Northwest]

Make sure you get the kit with adjustable augers as the ones that come with loads of fixed ones or worse still the mganetic version, don't work so well.

Thank you, this sort of quality info saves a great deal of time and money.

 

[jcampbellsmith]

I use a collimator to roughly align and sight in a scope. However it is essential that the rifle is then checked on paper, before being used in anger.
Regards
JCS

 

[Cottis]

Unless this results in basically a true zero first shot, how is it better than bore sighting on a white target board? Assuming you have a turrets that dial true and can make a telling shot from a rested position, it takes two shots to zero a rifle if you mark your target board correctly.

How exactly does it level a scope? I get that the augur sits in the muzzle end of the barrel and that you can level the crosshairs relative to that but how do you know the augur is sat on the horizontal plane? Do you level the rifle action and then level the augur to that? I always look at various methods for levelling rifles/scopes but always feel there is still a degree of coin flipping going on unless you know there is a point on the rifle somewhere where you can confidently take a level measurement. If that can be found, then levelling the crosshairs against a plumb line is dead easy. The question is, can that level be confidently accepted? I end up often eyeballing all these things and then just using a spirit level in the field to vertically align a target board and test it out that way. I mean I am only shooting out to around 400yds, so don't need absolute perfection but it would still be useful even out to those distances where unwanted cant is definitely undesirable. I am sure that if I shot some of my rifles out to 800yds, I would see lateral misses that were down to my rifle/scope setup

If this unit can do this perfectly, I can see a use for it.

 

[Northwest]

How exactly does it level a scope?

If you think about it, aligning the upright line of the reticle to the straight up and down lines of the collimator grid it has to be level.

 

[Cottis]

If you think about it, aligning the upright line of the reticle to the straight up and down lines of the collimator grid it has to be level.

I understand that. I could mount a scope and align the vertical crosshair with a plumb line. The scope would be level as such but if the rifle isn't?

So I suppose my question is, how does this piece of kit ensure your rifle action/bore is level before the gizmo thingy trues up the crosshair. I don't think I understand how it does that bit.

 

[jcampbellsmith]

If you think about it, aligning the upright line of the reticle to the straight up and down lines of the collimator grid it has to be level.

I don't think so, both can be off. Typically when I am using the collimator, I have the rifle aimed at a vertical spirit level at the end of the garden and have levelled the action as well. When I want to check the vertical, I rotate the collimator out of the way, and then check the scope reticle against the spirit level. When I'm happy, I tighten up the scope mounts.
Regards
JCS

 

[geoffw]

Saved me time and money over the years, well worth it. Good for 1” or so at 100m first shot.

 

[User00040]

However it is essential that the rifle is then checked on paper, before being used in anger.

Correct, and often a very slight (less than 2-3 MOA) of correction will need to be applied depending on how the scope/mount/barrel relationship is (considering that not all barrels are clocked true, even if the scope is perfectly aligned on the reciever, and the barrel flexes anyway during firing).

The true value lies in being able to 1. get very close to a correct zero from the 1st shot and 2. take a picture after zeroing to show where the alignment is, for future reference if the rifle/scope is knocked or dissasembled for cleaning etc.

If you think about it, aligning the upright line of the reticle to the straight up and down lines of the collimator grid it has to be level.

The rear end of the collimator can be screwed off so that a small torch can be shined through it (and hence the scope, from the objective lens end) which will give you a nice overlay projection onto a white wall in a darkened room. The use of a window or door frame that is checked with a spirit level to be a known 90° makes the process very repeatable without faff of hanging a pendulum etc.

In terms of levelling the collimator itself, you need to make sure it is scrwed onto the flat of the expanding auger properly, and then once secure in the chamber it is easy to see when the inner reticle is 'level' with the method described above.

 

[User00040]

Correct, and often a very slight (less than 2-3 MOA) of correction will need to be applied depending on how the scope/mount/barrel relationship is (considering that not all barrels are clocked true, even if the scope is perfectly aligned on the reciever, and the barrel flexes anyway during firing).

The true value lies in being able to 1. get very close to a correct zero from the 1st shot and 2. take a picture after zeroing to show where the alignment is, for future reference if the rifle/scope is knocked or dissasembled for cleaning etc.



The rear end of the collimator can be screwed off so that a small torch can be shined through it (and hence the scope, from the objective lens end) which will give you a nice overlay projection onto a white wall in a darkened room. The use of a window or door frame that is checked with a spirit level to be a known 90° makes the process very repeatable without faff of hanging a pendulum etc.

In terms of levelling the collimator itself, you need to make sure it is scrwed onto the flat of the expanding auger properly, and then once secure in the chamber it is easy to see when the inner reticle is 'level' with the method described above.

Pictoral demonstration of the above, forgive me that the colimator itself is not perfectly level in the picture but rest assured everything important is 'level' (action/scope relative to the horizon).

Also note slight windage offset required due to stock cast-off.