300 RUM workup

[N.ID.hunting]

Howdy all. New to the forum and distance shooting in general. I've been reloading for a year or so now. Just bought a 300 RUM and trying to work up the magic load/bullet. Currently, I'm trying to get a 215 grain berger target hybrid bullet to work with 87 grains of H-1000. This is my starting point, and shooting yesterday, the groups were a little wide at 200 and 300 yards. But when I move back to 450 yards the group tightened up significantly. Sub MOA. I'm wondering if anyone would be so kind as to give me a tip or two to save me time getting this bullet to cooperate. My main question is should I go up or down in grains to tighten up the groups? Thank you very much and please forgive my greenhornedness.
Remington model 700
1:10 twist
26" barrel
Leupold vx 3i 6.5-20 x50

 

[Wedgy]

Do a ladder test as far of range, at least 500 yards to show the spread and it really helps if you have a good chrono like Labradar to monitor the velocities, the more data the better. Depending on the range you plan to hunt the 230 grain might be a good bullet as well. The OTM shoots well from mag length.

Ladder testing at 1k- Detailed article and video

Jason Baney has got an absolutely great video and article on ladder tesing LR loads at 1k. This by far the most detailed explanation of how to, what to look for you could find. You will have to excuse him in the video, looks like he had a bad hair day!:D Long-Range Load Development Lynn...

www.longrangehunting.com