I gotta get 1GR something to relieve the pressure...

Any ideas?

This is just personal preference, so YMMV, but here's my take on the gadgets and toys.

Bolt guns, and/or anything you can look down the bore from/through, from the breech end.... I just adjust the scope to see the same sight picture as the bore shows. A 3-4" orange dot, or anything you can make out with the naked eye will work.

For an AR, I assume removing the complete upper from the complete lower would suffice.

With a solid rest, look down the bore, with your eye centered as much as your eye can make out, while examining the rifleing image, at a mark or target at 100 yards. Then, with certainty of no movement of the bore/gun, look through the scopes sight picture. You should be able to make adjustments to get these two views identical to a level that is sufficient, and likely even superior to that available with conventional bore-sighting tools.

If you do this at a 100 yard target, you should be a few inches high at 50 yards, and a few inches low at 100 yards with actual fired shots, depending on the time and care taken during the bore-sighting process. Left to right will likely be off just as much, or, it often is with my eyes anyhow.

Either way, from my own experience, it seems to be a superior method to the tools and gadgets sold for this purpose.

I favor the Browning BAR rifles, and this bore-sighting method has never been an option, since one can't look down the bore of these rifles from the breech end. For these rifles, and the 10/22, and the like, I just start shooting at 25 yards on a large piece of cardboard. Then to 50, then 100.

I did buy one of Leupolds magnetic bore sighting tools a year or so ago, and have had results that match conventional bore sighting tools.... 3-9" off at 100 yards.... and even worse with BOSS or brake equipped barrels... understandably so.

I have not tried any of the laser bore gadgets, but since they are, (the ones I've seen), cartridge specific, I've opted to stick with my ancient and archaic ways.