i used my leupold magnetic boreshighter this year to zero my ml and i have to say that was about the smoothest sighting in session i ever had. Brand new scope in new mounts....i was zero'd on my 3rd shot...couldnt believe it lol. At my range we have a target board at 50 so thats where i usually start, i like to just use sandbags as a rest and although i shoot bh209 i like to swab between shots. I learned a trick from somewhere on here, take a smaller diameter brush and wrap a seasoned patch around it and use that to swap, you dont lose your patch and it goes quick.