It might seem as if I'd forgotten about this topic, after I played a part in getting it started. Not so, I simply hit a snag.
Wal-Mart had laser boresighters on the shelf, until I went to get one. Then they were suddenly sold out (happens to me a lot).
After being assured that they would have more "next week" for over a month, I finally got one yesterday. It wasn't the $39 Simmons they had before, it was a $42 Laserlyte. But hey, that's the way it goes at Wally World.
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(click on the photo for a larger version)
Use
this link to got to the product page at Laserlyte's website. The one on their site is black, mine is red (a "Wal-Mart Exclusive"), but otherwise they are identical.
I'd briefly considered making an adapter that would screw onto the small laser that I already have, and using that one as a boresight. But two things stopped me. First, it's not really a very good laser. It doesn't have a sharp 'dot' even at close range. At boresighting distance, the dot would be very ragged and blurry. Second, and most importantly, it had already been mounted and re-aimed a couple of times before this project. And any tiny movement of the adjustment screws makes a huge difference in POA. Getting it recalibrated to point accurately along the centerline at any distance, while not impossible, would be difficult and time consuming. The Laserlyte is factory-calibrated.
Also, the adapter for the Laserlyte unit will be easier to make. All it really needs is a reduced bore (between .22" and .50") that will be concentric with the bore of the cannon.
So now I need an adapter. Hopefully this won't require another month...