I recently used my bushnell bore sighting tool to bore site the scope for my new custom rifle, I was very very close, only a couple inches low and .5" left, at 100 yards. I got to thinking why on some rifles I get the bore sighter right on the money and others I can not the hit the broad side of a barn, then I got to thinking if the bore sighter is pushed all the way in and the crown is cut a little off wouldn't this cause you to have a cocked over bore sigther?? anyone else noticed this??

I just know you didn't put a boresighting spud in the bore against that crown... Do yourself a favor and throw that Bushnell POS as far as you can see and invest in one of these.

http://www.leupold.com/hunting-and-shooting/products/mo...minated-boresighter/

You won't damage the crown with it.

Boresighters are used to get you on paper or close. I prefer picking a dirt clod on the backstop to use as the initial target while performing coarse adjustments before going to paper. Visually watching the impacts near the clod makes bringing the groups on paper, fast.

If your bullet is impacting within a couple of inches of where your scope was boresighted then be happy. It doesn't happen like that very often. There are a lot of things that influence the flight of the bullet and having the bullet actually hit the spot after boresighting is rare. Cherrish the moment but don't dwell on it.

quote:

Originally posted by Westpac:
I just know you didn't put a boresighting spud in the bore against that crown... Do yourself a favor and throw that Bushnell POS as far as you can see and invest in one of these.

http://www.leupold.com/hunting-and-shooting/products/mo...minated-boresighter/

You won't damage the crown with it.

Boresighters are used to get you on paper or close. I prefer picking a dirt clod on the backstop to use as the initial target while performing coarse adjustments before going to paper. Visually watching the impacts near the clod makes bringing the groups on paper, fast.

If your bullet is impacting within a couple of inches of where your scope was boresighted then be happy. It doesn't happen like that very often. There are a lot of things that influence the flight of the bullet and having the bullet actually hit the spot after boresighting is rare. Cherrish the moment but don't dwell on it.

I thought that might get a rise out of you, I was extremely careful when I put it in there,

I use the free, set it in the rest on the kitchen table facing window, remove bolt, center in the bore the tennis ball on the post @ 300' in back yard then adj crosshairs to ctr. of same, Bore sighter. Works every time

quote:

Originally posted by tsturm:
I use the free, set it in the rest on the kitchen table facing window, remove bolt, center in the bore the tennis ball on the post @ 300' in back yard then adj crosshairs to ctr. of same, Bore sighter. Works every time

For about 20 years, I used a Bushnell boresighter which one of my hunters I was guiding for moose in 1969 gave me (he had brought one with him). It worked fine and did not damage any of my hunting rifle bores to any detectable extent.

However, almost 20 years ago, I switched to roughly the same system tsturm uses above. The only difference is I use a number board at our range as my object to sight on. Saves having to lug along any boresighter in my already overburdened shooting truck, plus I don't have to assemble/disassemble the bore sighter or pack/unpack it. And yeh, free is great too.

In lever actions, & semis where I can't look down the bore (like the Garand and M1-A's), I still use the Bushnell. Part of my "if it ain't broke, I don't have to pay to fix it" approach to life. <Grin>.

Bore sighting tools are a must have and very useful in a number of scenarios which include semi-autos and zeroing open sights. I have used the Sweeny Site-A-Line for the last twenty years. The bore sighters have a calibration engineered in them including velocity, caliber, barrel diameter, and scope height. More or less the standard and magnum common ballistics and sporting firearms. Set-ups outside the calibration range will be erroneous.

The crown should not interfere.

Lever actions & Semi-autos they still make them?LOL

Yep, still making the big .45-70 Government lever gun. New addition is the .325 WSM in the Browning BLR. The .338 Winchester Magnum in the BAR, M1A's and M16's alive and well.

I use the LaserLyte one from Cabelas. I generally sight in on a telephone pole behind my house. After gun is on at the range I check it at 15 ft and note the difference on a cardboard target I have that has 1/4" marks on it and is only about 6"wide and 12" tall. I note the setting (offset in 1/4" marks) on the back. When I get to camp I check again with the laser and compare readings. Works perfectly and is very small and light to put in duffle.

I've used the Busnell POS for about 30 years now. Don't remember the actual year I got it. With mine are two different types of spuds-straight, one-caliber size, and the "adjustable arbor" type that have expanding fingers that spread out to touch the bore walls, and a cone-shaped end that you push into contact with the lands at the muzzle. The spuds appear to be made of steel, so must be inserted carefully so as not to impact against the lands at the muzzle. The expandable arbor type are apparently made from plated brass, and appear to me to be too soft to damage a steel muzzle crown. In addition, they are tapered, so they never "bag" into the lands as you insert them.

I agree with the idea of using a rest and actually looking through the barrel to boresight the weapon. BUT you cannot do this very easily while in a primitive hunting camp. It is in such situations where the optical collimator type boresighter is most useful.

More than once, I've had trips over backwoods roads vibrate a scope mount screw loose, and had to re-zero the rifle after tightening up a screw or two. Having the boresigther along made it easier, as I record the point to which my reticles are pointed on the sighting grid after firing and zeroing. That way, I just crank the scope adjustments back to that spot, and will be very close to where the rifle was shooting before the mishap. Still have to fire a round or two for comfimation, though!