View Full Version : BSA boresighter

Scarecrow Repair
01-14-2007, 12:43 AM
I bought a BSA boresighter (http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=766064) and have some questions about using it.

For those who don't know anything about it, here's a quick description. There are two parts: an optical piece with a clamp below into which you insert one end of a caliber-specific rod (the arbor); the other end of the arbor goes into the muzzle. The optical piece sticks above the barrel about as much as a scope but the exact distance is not critical, and it is big enough that it ought to work with just about any size or offset. You rotate the boresighter until it is vertically above the barrel and look at it through your scope. The optical part has a grid of lines on it. If you think about it for a moment, pretty much by definition the scope vertical and horizontal reticle lines can only match up with the grid lines if the optical part is exactly vertically above the barrel; if it were off to the side even a little, its grid lines would be rotated and the scope lines could not line up with them ... but if your scope is rotated too, well, trouble!

So, I got it and played with it some, but it only barely got above freezing here so I decided that trying to actually sight it in would be somewhat tricky with shivering fingers. I don't know yet how well it works, but it seems like it ought to.

I have two questions for anyone who has used one. I think Bushnell sells the same thing, so you Bushnell boresighter users can chime in too and tell me everything I have done wrong :-)

First, I think this is only useful for zeroing the scope windage. It's a very clever idea, I like it, but I don't see any way it could be made to work with elevation also. However, having used the boresighter to zero windage, elevation zeroing would be easier. And then, having zeroed the elevation, if you put the boresighter back in and write down exactly where the scope lines are in the boresighter grid, you could then restore that zero after taking the scope off and putting it back on. Or if you want to change zero for different yardages, just write down all the different settings and it would be pretty easy and quick.

Have I got that right?

Second question ... the only arbor I have used so far is the .22 and it doesn't lock in very tight at all in the barrel. I found that if I was trying to hold the rifle up and look through it, it took only a very little movement for the boresighter to swiing around and end up underneath the barrel. I thought briefly of doing the alignment upside down, but that didn't appeal to me. I ended up resting the rifle on a stack of books and that worked, altho it is very touchy.

Is that normal? Is it the same for all calibers?

Lastly, the arbor goes in the muzzle ... is this something a match shooter would never do for fear of damaging the crown or rifling? It has a small brass (looks like) spring on its side to apply pressure to keep it in place and it doesn't actually have to slide all the way down to the crown, it can stay out a half inch and work fine.