My .257 Roberts shot better with those SPS 115 partitions with the stubby ogive than any other bullet I ever fed it. I posted about it a while back. I used Ramshot Magnum and it went consistently sub MOA. Never did that well before. After a bunch of trials I settled on 50.8 gr at 3000 FPS.
Here's the thread where I wrote about it. There is some earlier work-up posts if you scroll up but the bottom-line, end results are here:
Good .257 155 stubby partition loadCheers,
Rex
