Thread: clarification 7mmRm + ar2217 + hornady eldx 150g

Originally Posted by Larskramer

I have brought a buller puller and will pull these projecties and start at a higher amount of powder. So... a good range would be starting at around 68g of 2217, and go 69g, 70g, 70.5, 71g, 71.5g, 72g, 72.5g and 73g? Would 4x rounds of each be sufficient for a good group test ? or 3 or 5 ? With a bullet puller, Can I still use the projectile again ? or is it best not too? I will do some more of these developments next week when I am home so gettin all the information by then would be great.

I would not start that high. Its going to suck if you get to the range and find your start load is over pressure or close to, and you cant shoot any of the other 45rounds...

This is what I would do.
Load a ladder, one round of each, going up in .5gr increments from 64gr up to 72gr.
Start by shooting the 64gr cartridge and work your way up keeping an eye on pressure. Once you reach pressure signs you now know that your reloading efforts should be focused under that threshold.
Ideally you would also have a chrono, then during the initial pressure test you could look for flat spots in velocity and focus your loading efforts around those points.

If you must shoot some groups or test "accuracy" on your first outing/test, then I would highly suggest only taking multiples of lower powder charges. eg take like 5 x 64gr, 5 x 64.5gr, 5 x 65gr.... certainly don't take multiples from 69gr up to 73.... that's asking for a short day at the range. To be clear you are proposing to start at the book max and only work up higher from there. I understand others run slightly above book max, but that's not a starting point.
There are just as many people who cant reach book max without pressure, so there is a chance that ALL of your rounds will be un-shootable in your rifle which would make for a very inefficient load development process.

I would start at 64gr and go up from there.