fishead

what are the best bullets for breaking in a new Remington 7 mag, if any and how?

homers brother

What matters more than "bullet" is the break-in procedure you use on the barrel itself. That question will likely elicit a number of different procedures. For most rack-grade rifles, it's not that big a deal to start with. I suggest you ask this question over on the "Guns" forum here, rather than in "reloading".

Hairtrigger

Follow this guy's break in procedure to the last letter.
http://www.youtube.com/watch?v=TRRahHX9Zkg
In real life you will make very little difference how you break in a barrel on a hunting rifle.

devil dog

THATS JUST SICK!!!!!!

bigcountry

I like cheap ones like coreloks. Sometimes barrel breakin works, most of the time not. Its really a tool to get down to some serious load development. Anybody that shoots long range will see a new gun, have large velocity std. dev. the first 100 rounds or so. that should settle out. Following breakin procedures can lower that down to 20 rounds.

Breakin procedures are not what is wrote out there but to observe what is happening and make adjustments based off of that. If you see no copper fouling after two shots, then try 5. Keep cleaning and shooting until you see little to no fouling at 5. Try 10. But most likely what will happen is, youwill see copper fouling after each shot for 5 or so shots, and then you will see copper fouling after 3, and you can never get better than that.

Remnard

Most factory bores on off the shelf rifles will have pretty rough bores. If you look atthe rifling magnified in a barrel on a new gun you will see many jagged edges along the lands of the rifling. This will tend to catch copper and powder fouling and it will accumulate quickly.These barrels are mass produced and at one point I read that Ruger was paying $18 wholesale for barrels that they were putting on their rifles to sell us. Some of the guns I bought from them back then shot like an 18 dollar barrel too! What you want to do is break these edgesoff and smooth out those lands and grooves. If you don't they will catch copper etc, and form a high spot which will raise hell with your accuracy.
Buy some JB bore paste, non embedding compound. http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=1161&title=J-B~%20BORE%20BRIGHT
You will be amazed at how dirty your gun is after you clean it the conventional way, when you use this stuff after!
Try This:
Clean the gun before firing it.
Buy some cheap ammo, and some ammo that you would like to use for huntingwith the gun.
using the cheap stuff, After each round, run a bronze brush through the barrel several times, followed by a clean patch with solvent on it.
follow with a clean patch.

after 10 rounds clean the gun thoroughly, with a wet patch, followed by a bronze brush 2 strokes in and out for each round.
follow with another wet patch and a dry patch
Now use the JB bore paste per the directions on the container.

I would do this after the first 2 or 3 range sessions, and I would also try to shoot the tightest groups you can even with the cheap ammo. Don't waste the good stuff on break in.

You may have a good barrel, you may not. Whether you do or not, using this method will ensure that the gun shoots accurately and doesn't foul every three shots, causing accuracy issues.

Most premium barrel manufacturers use a variation of this method of lapping new barrels. It's one of thebasics to a good -long lasting -accurate bore.

handloader1

I would use a Hornady 175 gr. Innerlock. Good luck.