Has anyone used these ? What is the difference in the laser cartridge and the one that is inserted in the end of the barrel ? And what is the average price of these bore sights ? Where would you recommend purchasing them from ? Retail or online ?

i would recommend that you save your money and add a better scope. you have to remember that the laser light does not drop but your bullet does. so the laser will only get you in the general area. you can get this close by just sighting threw you barrel with your eye.i just think they are a waste of money. to each their own i guess.

I have a Cabela's laser boresighter, and it's saved me some time (not to mention ammunition) at the range.

True, you can't sight-in the rifle with it, but it was a big help to me with boresighting; got me to within a couple of inches, so when I got to the range, it only took a few shots per rifle to get it zeroed in.

If I only had one rifle, I'd spend the money on ammunition and range time, but since I've had a few rifles to boresight, it's been a big help.