204Ruger

Oh Boy...a new Cooper. Congrats. First one???
I've always figured that every Cooper comes to you with a minimum 4 shots down the barrel. I'm sure they don't clean between shots. I take a middle of the road approach and shoot 5 then clean, then repeat. The barrel tells me when it's ready. Some come clean and copper free in 20-30 shots. Some take a little longer. Strange as it sounds, I think I can feel the barrel breaking in based on how the patch feels going down the bore. I'm mostly looking for copper and trying to make sure I'm not burnishing it in to the barrel.
Use a good bore guide (Lucas) and whatever chemicals you feel do the job.

You'll like that Jard. Store the Cooper separately, preferably in another room. They have a tendency to multiply.

Sage advice, not that I knew Cooper's way, but about the manner in which I break in a barrel. Other barrel makers suggest very similar or slightly diffenrent, but they all work, Just slow and easy for the first few shots and do not over heat the barrel. And yes you will like that Jard Trigger, I have some and they work very well. Bill K

Congratulations on the new Cooper! I used to go into a shop in Boise quite a bit that stocked Coopers. They sure are fine rifles!

Barre break-in is a thing that has come about because people want it. It was 'invented' by a competitor of Gale McMillan's (that according to McMillan in a years-old public posting) to sell more barrels, since every round down a barrel uses up a percentage of its useful life. However, it has persisted because a significant number of people _want_ there to be a break-in procedure. They want to have a procedure, so the salesmen sell them what they want. Is there any harm in that? Whether you _want_ there to be benefit or harm will be far and away the largest determinant of whether there's any harm in it, or any help.

My break-in routine is: Go shoot. When I'm done, I clean the barrel and see how it is. If I shot, say, 20 or 30 rounds and clean-up takes 2 hours, I'll be disappointed. Maybe I'll scrub it with bore paste or something like that, or maybe I'll just shoot it a little more at a little higher rate of fire next time. Or maybe not.

When I got my Cooper, I followed the break-in procedure that came with the rifle. Yes it is tedious, but I have to believe that it worked out really well. After a day in the rat patch and sometimes over 100 rounds down range launching said rats, the rifle is a lot easier to get clean. Patches down the tube run a lot easier, no matter bore cleaner or copper cleaner. As for accuracy, my 20VT Cooper shoots bug holes at 100 yards, with confirmed kills with a laser range finder, out to 450 yards. Maybe it was barrel break-in or just being a Cooper, I can't say for sure. I did change the trigger out with a Jard 10oz trigger too. Love my Cooper with the Jard!