**UPDATE** Looking for load data for 338 lapua improved

[odoylerules]

I have an 8lb jug of RE-33 for my lapua improved. I've shot 100 fire forming rounds through it with 93 grains of retumbo and am ready to start load development. I'll be shooting 300 gr Berger Elite hunters out of a 30" Proof barrel.
Looking for any load data out there to get started. My smith gave me a window of 98-103 grains. I know every rifle is different, and I plan to test for myself. I would like to hear what others are loading and the performance they're getting with the same combo,
Thanks

 

[odoylerules]

Well no love from anybody...
I guess I'm on my own. Loading up a ladder test. I'll report results later if anyone is interested.
Here's one of my finished rounds next to a 5.56

 

[el matador]

I would fill the case all the way to the top with some RL33 and weigh it. Multiply by 90% and that will be pretty close to your max charge. I've done some testing with this powder in my 338-378 and I didn't see significant pressure signs until I was compressing the heck out of it. Lapua brass can be pushed harder than the Weatherby stuff, too. For more consistent reloads using compressed charges you may consider using a drop tube. My cases hold 132 grains of powder when filled to the brim and my max loads were 118 grains.

I got really good velocity and decent accuracy with the RL33 in my gun. I only found the accuracy by pushing it hard though, and if you understand the Weatherby brass situation you'll see why I'm not liking the RL33. Brass are north of $3 each and they don't take abuse too well.

With your barrel length it should be easy to hit 3000 fps with those bullets. Hopefully you can find the accuracy you're looking for with a nice comfortable case fill.

 

[el matador]

One of the more widely discussed versions of the 338 Lapua Improved is Kirby Allen's version, the 338 Allen Express (or AX). You can probably find a good bit of data by searching. Here is a thread about the AX with RL33 to get you started:

https://www.longrangehunting.com/threads/338-allen-xpress-rl33-load-development.120353/

 

[odoylerules]

I shot a group/ladder test at 650 yards. Temp was around 55° and winds were changing from 3-6mph. Obviously I'm most concerned with vertical. The 103.0 to 103.5 node shows some real promise. VERY tight vertical with only one "flyer" and even that was 2" of vertical. It looks like 104.0 is a scatter node as the vertical really opened up.
338 lapua improved
Lapua brass, fed gm 215 primers, RE-33, 300 gr Elite hunters. Base to ogive 3.0350 (.015" off)
103.0 grains 2951 avg velocity, ES-9
103.5 grains 2977 avg velocity, ES-13