The action I built my 280AI on had a Shilen 280 Remington barrel that was shot out.I had it put on in 1981,and used it a lot,the total round count was 3,400.Accuracy went from groups less than an inch to groups over 2.5 inches.I have a lot of once fired brass and it made sense to chamber the new barrel in the 280AI rather than the 7 Magnum that I was going to chamber it in.I bought a deep chambered Select Match varmint contour barrel from Shilen and fitted it to my M700 action,making sure I kept the head space pretty snug.A .002 shim on top of the Go gauge will stop the bolt from closing.I had a bunch of 140 grain flat base bullets that my old barrel liked to shoot and they worked fine for barrel break-in,function testing and rough zeroing the scope.I started with 50 rounds of Hornady 280 Rem. brass.I seated the bullets to jam .020 into the lands to make sure the brass was tight on the bolt face so the fire formed brass wouldn't stretch too much during forming.Powder charge was book minimum for the 280 Rem. using IMR4350.This method fire formed the brass perfectly to my chamber,and with the Redding FL die tight on the shell holder,it's sized to about a .002 shoulder bump,which lets the bolt work smooth with minimal working of the brass,and very minimal trimming.I cleaned after every shot for 30 rounds,which I know was more than needed for barrel break in,but I had the time and wanted to take no chances on making a very nice barrel get carbon buildup in the throat.After the first 30,I cleaned after every 5 shots.When I was doing load development,I also ran 10 rounds every session of once fired Remington brass through it until I had another 50 rounds of brass.I also worked the brass over by uniforming and deburring the flash holes and trimming it all to uniform length.I now have an incredibly accurate rifle and 100 rounds of brass to work with.After 12 loadings,I loaded the Hornady brass with hunting bullets and I'll discard all that brass after it's spent.I use the Remington brass to shoot long range steel and or targets.It's a simple setup,neck turning wasn't needed,and it'll do anything the 270 Win can do,along with things the 270 can't do.I doubt if one of them will turn 3,000 FPS with a 160 grain bullet with ease like the 280AI will do.Yes,it took a little work,but I'd do it all again tomorrow if I had to.Well,I am doing it all again,only this one is a 7 pound 338-06 that'll be ready to go this coming fall hunting season.Sorry for the long post,but I wanted to pass along any info that might help somebody.
