Home Forums Hunting & Shooting Hunting Optics Collimators?

For many years I used a Collimator from Cabela's with good success. It was damaged so I got another one. It doesn't seem to be of the same quality and the results vary, but at least it got me on paper most of the time. Lately it doesn't even do that.

Since it was inconsistent, I just reverted to the old pull the bolt and look through the bore system which has worked much better, until I bought a new 10/22. Kind of hard to look down the bore on the little rascal.

Since I haven't been too happy with my collimator, I picked up a cheap little Bushnell Magnetic boresighter to try it. I used a straight edge and level to try to align the magnetic job with the scope. Once again, the rifle shot way off even at 25 yards.

Tried both boresighters again and there is a 2 inch elevation difference and a NINE inch windage difference between them!

I ended up sighting in by shooting at clay pigeons with a spotter telling me how far off I was. That worked, but took a lot of time and ammo and two people.

So, What do you guys use to bore sight semi-autos? I've looked at some laser units, but they seem to have poor reviews.

Also, is there a math formula for using a 100 yard grid when you want to sight-in for 50 yards?

I have been using an old ( probably 30 years old) Bushnell with the 3 adjustable arbors. Some guns are very close and some not, but most at least are on paper. It seems the laser boresighters are the hot thing now.

I use a laser bore sighter and I'm on paper using them. I use it at dusk when I can see the red dot at 100 yards.

I have a Leupold magnetic, if the muzzle crown is true, it will get you within 4 moa at 100, great ammo saver. If you record the grid intersection point before you take off a scope and/or mount, it will generally get you within 2 moa of original zero. There are a few tricks though to getting the most out of it. Nothing beats actual bore sighting on a white rock across the river from my shop vise about 2/3 a mile away.

Agree with all you said. Looking down the barrel is best but the magnetic sighter, while it never lines up dead center, does seem surprisingly consistent to the same intersection.

I have an old Simmons collimator with spuds for most bore sizes. It isn't precise, but it will reliably put the first shot on paper within 6" of the POA. Once I have that first hole in paper, I can aim at that point and move the reticle to the center of the intended POA. I can zero with 2 shots, but usually shoot a 3rd to confirm the zero.

Never have used one. They seem a bit hokey to me.

I just look down the barrel, or if that's not possible I'll shoot at a shorter range, or use a big piece of cardboard.

I've got one of their now discontinued "Zero-Point" magnetic boresighters. As you pointed out, works great if the crown is true. For those rifles I have an issue with I use a Sight-Lite laser boresighter which works extremely well, always on an 8.5x11 at 100yds.

A really great use for the compact zero point is checking a zero IF something happens. I record my zeros on printed grids and take pictures with my phone. If a rifle gets knocked, it only takes a minute to slap the boresighter on to confirm zero. Sample grid picture:




I've also used the above method when swapping scopes etc. It works very well for that purpose. I can do it with my laser boresighter also (record a zero), but the magnetic Zero Point is just easier.

As I have pointed out on these threads before, the highest and best use for a collimator/"bore-sighter" is not to bore-sight rifles--most of which can be bore-sighted the old-fashioned way, by looking through the bore.

Instead their best use is to make sure a scope is lined up reasonably close to the bore during mounting, which not only provides the maximum amount of adjustment, but in general allows the adjustments to be more accurate.

But one thing I've also mentioned is any collimator should be checked by putting it on rifles that are already sighted-in, to see how close the collimator comes. Obviously this won't be the same for all rifles, due differences in weight, recoil, barrel contour, and even the shooter. However, you can arrive at a pretty good average point, whether the collimator uses adjustable studs like the Bushnell or a magnet. My Bushnell, for instance, will get just about any rifle close at 100 yards if the scope's adjusted so the reticle is one "square" high and dead center.

I have three collimators right now, the Bushnell that's been around at least a quarter-century, plus a Leupold magnetic with a screen and a Wheeler Engineering magnetic laser--and use all three, depending the gun. The magnetic models can be used on a far wider array of firearms, including 12-gauge slug guns--where I really prefer to shoot as few rounds as possible when sighting-in.

All of this is described in far more detail in Chapter 10 of the book Modern Hunting Optics. (www.riflesandrecipes.com)

Can't blame you for not wanting to shoot a 12 gauge slug gun more than necessary! One season of Iowa deer hunting with a Savage 210 was enough for me, but 20 gauge slugs seem to kill Iowa whitetails just as dead and the recoil is a lot more pleasant.

Same here, an old Bushnell from thirty years ago.

Mine is a half-ish grid to right of centre on all rifles I have used, elevation varies.


Probably should adjust it but don't see the point in doing so.

I have the same one, and my gunsmith friends use the older Bushnell. Mine is at least 40 years old.

I got a Jap Tasco 25-30 years ago on sale for $8.00 that had all the different "spuds", was not adjustable like the Bushnell. It was OK, just OK.

I do the same thing with a Bushnell magnetic boresighter. Gets me surprisingly close to POA.

Yup, an old Bushnell. Works on bolt, lever, semi-auto, etc - pretty much any scoped rifle .22 to .45 caliber. I vaguely recall you used to be able to buy larger arbors but have never seen one.

They are still on the market, and the current version includes a .17 caliber arbor.

How well do they work on stainless steel barrels?

I either have or have had every type of these devices mentioned except the laser pointer that goes in the end of the barrel. how well do they actually work?

Depends on the alloy - some stainless is magnetic, some isn't. 416/416R stainless barrels ARE magnetic.

Just fine on every SS barrel I've tried it on, which is a bunch.

Dad had a converted Mauser 98 8x57 that he sighted it over the car hood and minute of cardboard box was good enough for dad. The night before opening day one of the guys pulls out his new collimator and wants to check and adjust everyone’s rifle. As a 13 year old kid, who was I to suggest that wasn’t a good idea. Admittedly the deer camp guys weren’t really serious about their deer hunting, but the time for that bore sighter was way before opening weekend.