I just picked up a Weatherby Euromark in 300 Weatherby that was listed as used. On inspection, we don't think it has been fired or fired only a couple of rounds. There are no wear marks at all on the bolt face. The barrel cleaned up with just two patches of Shooter's Choice and there is no sign of wear on the muzzle. I plan to shoot it this weekend and break the barrel in like any new barrel.

Does anybody have a favorite load for this caliber with 165gr or 180gr Barnes Triple shocks or maybe the 180gr Accubonds.

Ed, the Euromark is a nice edition of the Mark 5, with the oiled wood. Good luck with it.

Thanks Biebs. I set one up for a friend a few weeks ago and hated to give it back. I just hope this one shoots as well as the other one.

Man I love Euromarks, excellent choice and an outstanding chambering. I have a 340 Alaskan that I want to put in a Euromark stock when I find one.

Envy comments aside , a thought that has crossed my mind recently is breaking in a barrel with Barnes (or other 100% copper) bullets. Soft as they are, I was wondering if using a simple cup and core bullet for break in would be a better idea. The 340 is unfired and I haven't gotten it to the range yet. I don't have any brass for it so I bought the only 340 factory ammo available which is Barnes 225 grain bullets. That said, Barnes bullets are the only ones I load in my other rifles and all but one was broken in with them. Your thoughts?

Ken....

I have the Accumark in 300 WinMag but it has a Kreiger barrel so I don't know if it's a good comparison since your barrel may be a different brand. Mine likes the heavier bullets like the 180 and 190 grain. I use IMR 4831 and get .6" with 71 grains at 3010 fps. The 300 Weatherby has 7% more case capacity so that should be a good place to start working up.
My gun is very finicky about what bullets it likes and at first I was very frustrated with it. I found that it likes the 180 Barnes TTSX and heavy match bullets but is lousy with the 165 and under stuff. Sounds like you have a very nice rifle so enjoy it....I have enjoyed mine.

Heat--I fired 6 rounds of 165gr Sierra's to start with cleaning after each round and by the third round there was barely any fouling I could see at the muzzle. I used a brush with CR10 after the first 2 rounds and it did not turn dark blue, it looked like the brush disolving only. I think the Barnes will be fine to break it in. I think the main purpose of those first few rounds is to smooth out any rough edges.

sid--I shot a few groups with the 180gr Barnes TSX's and it grouped about .5" to 1" groups with RL22. Velocity was 3150 to 3260 with the loads I tried to start with. This rifle has the 26" #2 contour barrel.

Those are fantastic groups with great velocity. You are pushing 4k ft lbs of muzzle energy and it will be more than accurate enough out past 500 yds if you can hold it steady on game.
I put a Bushnell Elite 6500 4.5-30x50 on mine that I was using as a long range target scope. I like the combo so much that I am putting the 2.5-16x50 I had at first onto a 376 Steyr. You have a really nice rifle and I do not think you will ever be disapointed with it. Another thing I like about Mark V actions is the smooth solid bolt that doesn't wiggle when cycled. And it's a short 54 degree throw.

I plan to shoot a few more loads this weekend and see if they are as good as last week. If those work out, then I will take it to the gunsmith and get the trigger adjusted down to 3 lbs, clean up the barrel channel and bed the action.

Good to know Ed, thanks. It appears you are certainly on the right path for some accurate loads. I use Bore Tech Eliminator for cleaning so I suspect I can get most of the copper fouling out as I break in the barrel.

Sid, US made Accumarks come with a Kreiger Criterion barrel which is made from the same blanks as a Kreiger but are button rifled as compared to cut rifling. Just throwing in some info for ya.

Ken....

I shoot the 168 TTSX with RL22 from my Ultra Lightweight in 300Wby. It's a 26" modified #1. I shot loads from 1.5 grains under to 1.0 over the Barnes Manuel max with no extractor marks, sticky bolt, or flattened primers. 1.0 grains over max gave me ave MV of 3412 and put 5 shots right at .9" with the first 3 at .7". RL22 and 130 grain TSXs shoot even better from this rifle.