I will receive a new rifle pretty soon, and this time I want to do a proper barrel break in.. Never done it before, and have read some many different procedures..
How do you it?
How important do you think it is?
What kind of solvent do you use?

Anders, you may want to use the search facility over on the Gunsmithing forum - this subject has been discussed at length of late.
Good luck with your new toy!
- mike

Thanks a lot Mike.. I`ll try that!

Anders,

I break them in by shooting them. My shooting however is usually just two or three shots at a time from sporters. A new Kimber was "broken in" that way and cleaned when I got home.

Now with maybe 500 shots thru it I have stopped cleaning it at all. It's up to 82 shots now and it shoots just as well as it ever did. If the weather was damp I would put tape over the muzzle.

Check out Lilja's site:
http://www.riflebarrels.com/

good info here

Check out the gunsmithing forum as mentioned. It's been brought up many times so a search might be the quickest way to dig them up.
IMHO you'll get many good proceedures that will work. I think the key is to start with a clean bore, and clean often initially.
I'll not go on from there as this has been hashed and re-hashed.