Re: Thoughts on using a "mag" primer in the 22-250
I own two 22-250 Ackleys and usually like at least 55 grain bullets, but one uses 65gr bullets and the other 64gr. My particular theory is that the Improved version allows the use of heavier bullets at higher velocities than can be obtained in the standard 22-250Remington. I like H414, about 44 grains.
But, your question is can I use magnum primers. Yes you can, but more than likely you will be disappointed in the results. The mag primer will cause the slow burning powder to burn a little faster, which defeats the purpose. There are a number of suitable powders you can use in a 22-250 but you will not attain book velocities with any of them because of the unsuitable primer. At least, I doubt it? If you were hunting in subzero weather with a compressed load of IMR4831, well maybe that would be an application. At least some people see an advantage, but as the previous writer said; you don't need a mag primer (large rifle) until loading a 300WM, and even then, I use a standard Win large rifle primer with 80 grains of propellent.
So, you have a misapplication and if economy is important, you can use those primers but none of the loads in the manuals will work, so you need to be very careful
Personally, I'd ask around and see if you could maybe trade somebody for (what I use) Fed 210M primers, or just offer to sell them at a discount to somebody that has a suitable application.
Good luck, BB