I know the procedure the mfg recommends, but not the solvent/oil. If you were going to properly break in a barrel, what product would you use? I know to oil it, but what cleaner?

Manufacturers provide a break in procedure to avoid getting calls from customers asking for a break in procedure. A quality barrel doesn't need broken in.
If you're looking for a good cleaning product I'm a huge proponent of Bore Tech products. They do an excellent job and I don't have to use any type of brush. More barrels are ruined by over cleaning than they are by shooting.

For the most part its tooling mark removal in the chamber and start of the barrel proper, not so much barrel break in. Light cleaning after every round for the first 10-ish rounds, then light cleaning after every other round for the second 10-ish rounds is all that's needed. This first box of rounds is smoothing out the really small bits of metal left over from tooling -- bits of metal you don't want embedded into the bore or scratching the bore.

It really doesn't need to be an arduous process. I make a few passes with wet patches between rounds. With this first box of ammo I essentially cover three things at once -- smooth out barrel tooling imperfections, sight in the rifle, and gather initial muzzle velocity data.

As for cleaning solution, I don't think it makes much difference. Use your normal solution.

I would use something simple and not extremely aggressive.

I like the standard Hoppes #9 cleaning solvent for copper, Kroil is great for carbon and rust prevention.

Same here, Hoppes #9 and Kroil is what I usually use. But I also use some other lubes like CLP. I clean the barrel good before the first use. Then occasionally cleaning after they're broken in. If I notice accuracy starting to fall off, they get a good cleaning to remove the copper.

quote:

Originally posted by swage:
Manufacturers provide a break in procedure to avoid getting calls from customers asking for a break in procedure. A quality barrel doesn't need broken in.
If you're looking for a good cleaning product I'm a huge proponent of Bore Tech products. They do an excellent job and I don't have to use any type of brush. More barrels are ruined by over cleaning than they are by shooting.

I used to be in this camp but you are basically “bullet lapping” the barrel. Not removing the excess copper can build in some permanent irregularities in the barrel. Obviously this is for non lined barrels.

https://www.youtube.com/watch?v=3d0-FOEpAuw

You're not breaking in the barrel. You're doing exactly what Fritz described, you're removing rough machine marks from the bore. You need the burnishing of copper and carbon to layer the barrel in a uniform manner. If you keep removing that every few shots you're starting from scratch. Copper is softer than the 416 steel. It's not going damage the barrel. The hot plasma created in the bore from firing gets shot out the end of the barrel for the most part. If it makes you feel better, go ahead and run a patch down the barrel after 10 shots. Outside of that it's not necessary.

I personally shoot 5 rounds, cleaning after every shot. Cleaning means running a jag with a patch of Hoppe's 9 solvent, then run patches until they come out dry (not clean). I then shoot a set of 5 rounds and clean after the set is done. Then I shoot 10 rounds and clean after the set is done.

After that I consider it broken in.

Tony.

I used Butch's Bore Shine last line I broke in a barrel. Afterwards I used Breakfree.