Home Forums Hunting & Shooting Ask The Gunwriters Collimators

I just finished reading JB's article in Gun's regarding "Bore Sighters", and I have a question for the masses in general, and JB in particular.

I am comfortable with the ones with an arbor that fits in the barrel, but I have never figured out how to get the magnetic ones centered and precisely vertical. I level the rifle front to back and side to side in the rest, but then just eyeball mounting the collimator. I am not satisfied with that arrangement.

How do you guys set them up, get the correct height above the bore, centered, and vertical?

Regards,

GW

It's not supposed to matter that much. They work by mounting perpendicular to the muzzle; it's the angle (should be exactly 90 degrees) that's important.

Try this, if your barrel is short enough to reach - mount the collimator as intended, and look through the scope as you move the collimator around a bit. You'll be able to see when it's tilted, but up/down and side to side movements shouldn't have very much change in what you see through the scope.

With that said, I've gone to just bore sighting (visibly looking down the barrel) when possible because I get better results. I did have a Leupold collimator that worked well until somebody dropped it; despite no visible damage it never worked well after that. I suspect the magnet got knocked loose in the base and no longer holds true.

I have a old Redfield, gets me on paper at a hundred. Usually 6” low and 3” to the right. I’ve used it for 40 years.

With a magnetic muzzle collimator, I place them as close to center horizontally as possible on the muzzle, but also as close to the same height above the bore as the scope.

Don't really understand what's the problem is with getting them centered horizontally. This is easily done by eyeballing.

As for "precisely vertical," I've already mounted the scope so it's as square as possible with the center of the action/barrel, so I just align the collimator's reticle with the scope's reticle.

Are you looking for some system involving spirit levels, or something else to check your placement?

JB

Not really on the levels.

I have done similar to what you do, regarding using the scope reticle to align the vertical. I just didn't know if there was some trick I was missing on setting up the collimator correctly.

Not really. The biggie is approximating the same height above the bore as the scope. But as pointed out in the article, any collimator is an approximation, since so many other factors go into exact point of impact other than perfect collimator alignment.

Not a gun writer but what I have always done is pull the bolt so I can look down the barrel and center it on the bull, then move the cross hairs to center on the bull. This works with any rifle that you can remove the bolt. It always get me on paper at 100 yards

Thanks for the input everyone, looks like I am just over thinking the whole process.

GW

nimrodtracy,

The article was about using a collimator to mount scopes so they're reasonably aligned with the bore,which pre-solves a bunch of problems.

It was about not simply getting sighted-in--which is what most shooters assume is their primary purpose. As you just did.

I bought a magnetic collimator and I think it was well worth it!

I had one end of the barrel that wasn't exactly square (90 degree from bore). It was off by at least 1 degree (a little more than 60" at 100 yards.)

But that was very odd, I thought.

In general (all but that one rifle) it has worked very well. Now, the first thing I do when I mount a scope is check it out with the collimator.

Thanks to MD for another great recommendation.