I received 11 of them from Magman.
5 went to GoodGrouper for bc testing.
6 stayed with me for accuracy and velocity tests.
My "check against this load" is 300 SMK 101 gr US-869 for 2735 FPS. Accuracy is very very good, when I do my part. On the order of 1/2 MOA @ 200 yds.
I had to shorten the COL from the SMK setting to get the 265 Al Tips to clear the action unfired. My Rem 700 is single shot.
I calculated a starting/maximum usable load, mostly by scratching my head and pondering. (Don't do this at your house

)
103 gr US-869 went in on top of the FED 215GM. Three shots averages 2896 fps with a low teens ES. Group was a titch over 1/2 MOA @ 200.
I loaded one of the three remaining ahead of 91 grains of H1000 - 2803 FPS
Loaded another w/94 gr Retumbo - 2852 slight bolt lift pressure required
Both of these powders appear too fast for this bullet in my rifle. 26" factory sporter barrel.
The last load was 104 gr US-869 gave 2936, hardly any faster than the 103 gr load. BUT, bolt lift was a problem and a piece of wood was used to extract the empty cartridge.
The three shots were around 3/4 MOA @ 200.
I ordered a couple of hundred of 'em.
The bullet maker indicates that the BC is the same as the 300 SMK. If that's true it turns the 338 RUM into good solid 1500 yd rifle. Impressive.
Dave,
Got Milk?

Looking forward to your tests.