I have an old box of handloads that were custom loaded for one of my rifles. They shoot the tightest groups I've ever shot. The previous owner of the rifle is no longer among us. I want to duplicate them.
The notes on the box tell me what bullet and powder they are, and how much of each. The brass is easily identified by headstamp.
Is there any way to tell what primer is in them? They're doubtless large rifle primers (it's an 8x57 JS), and silvery colored. But beyond that, do I just need to buy a box of each brand and shoot for group (the load is a couple of grains down from max, so I feel fairly safe doing that), or can I visually identify them somehow? Or, since the manufacturer of these primers is a couple of decades' worth of lots past the lot in question, do I just need to try new primers anyway?
Duplicating the loads and the accuracy is a good plan.
I recognize that there are differences in primers, but it may, or may not affect the accuracy a great deal. I would try whatever primer is available. If that doesn't work as well, you can try something else. If you don't get the same accuracy you got with the present loads, remember it could be due to something other than the primer type.
Smitty of the North
Among other brands, the winchester primers are silver and the Remington are brass colored. So they are not remington and might be winchester. Best is to buy a box of winchester primers and try them. 8x57 are probably large rifle, not large magnum rifle primers.