I am loading these in my 416 WBY and getting awesome accuracy at 3100 fps.
Has anyone ever used them on game? What was performance like. Particularly concerned about expansion once velocity drops off a little, since it is not a tripple shock. thanx

Can't speak to the 300 gr at 3100 fps. Do have some experience with the 350 gr Barnes X at 2700 fps. (A mild load in comparison to what you can do at Max in a Rigby or a Weatherby.)

Blew through the shoulder of a Gemsbock at 35 yards with ease. Major exit hole. Not recovered.

Blew through the chest of a Hartebeast at 25 yards with ease. Major exit hole. Not recovered.

Blew through the belly of a Cape Buffalo with ease. Major exit hole. Not recovered.

Went through the same Buf just behind the shoulder. Major exit hole. Not recovered.

A shot while he was on the ground went in the rump, through the right rear leg (shattering the bone), up through the gut, and came to rest in the lungs. A good 5 feet of penetration.

The nose blew off almost to the cannula. Will weigh the remains when I get there.

The 350 holds up pretty well and penetrates like crazy. Not sure that the 300 could do as well.

Shot a bull Elk with the 300 X at 2900. Shot was about 175 yds, broke both front shoulders but stayed under the hide on the far side. Bullet weighed 288 grs. Good channel with very little blood shot. Elk was laying were hit.

Thanx guys. I got a couple of non expanding reports on another forum so I guess performance varies a great deal huh?

Well I tried it myself!

Ever get bored shooting at speed goats with regular (God's Chosen) cartridges? I did...again... so my 10 year old son Stephan wanted me to use the 416 WBY Mag for my third antelope tag, a doe tag. I was planning to use my 30-06 with 150 BT's but I said sure why not? Being a Crazy Greek explains it!
So my buddy Ray, Stephan and I headed west of Laramie Wyoming.
We located a mature doe 313 yards away. By the time I got set up for the shot she was 363 yards away. My 416 was stoked with BARNES X 300 grain with a stiff charge of H4350. Velocity at the muzzle is 3125 all day long as are the 1/2" groups at 100 yards.
I took the shot and the doe took off at a dead run. You can imagine my surprise! She ran 136 yards and dropped.
Upon closer examination turns out I hit her a little lower than I wanted. This is my fault due to the difference from 313 yards (initial reading) to 363 (when she stopped). Either way that 300 Barnes X did the job and beyond. Heart/lung--JELLO. Blood looked like it had been layed out with a pale!

Overall a great hunt!

PS: THE "BEE" STINGS!
entrance wound immediately behind front left leg



exit behind right leg far side---what a hole!



Doe --notice blood in backround!!




Stephan and I---Gorgeous Classicmark II




Ray and Stephan---Gorgeous Classicmark II