Originally Posted by locutus
The 1 1/2 is small pistol standard and the 5 1/2 is small pistol magnum.
The 6 1/2 is a standard small rifle. The 7 1/2 is a magnum small rifle primer. It's also MilSpec. The 9 1/2 is large rifle standard, and also MilSpec. 9 1/2 M is large rifle magnum.
And I agree they should just mark them standard and magnum to avoid confusion.
The 6 1/2 is "sort of" standard small rifle. If your small rifle is a .22 hornet.
Warning: Remington does not recommend this primer for use in the 17 Remington, 222 Remington, 223 Remington, 204 Ruger, 17 Remington Fireball. Use the 7-1/2 Small Rifle Bench Rest primer in these cartridges.
This 6-1/2 Small Rifle primer is primarily designed for use in the 22 Hornet.
Because the .22 Hornet is so common these days, it deserves it's own primer.
I suppose I can use my remaining 900 6 1/2s for magnum pistol loads.
Then there is the 1 1/2s:
Special Note: These primers are NOT recommended for loading high pressure loads such as 357 Mag, 357 Sig or 40 S&W. Please consult a Reputable Loading Manual for loading data.
The .40 S&W is not a magnum cartridge. In fact one must ask if 9 mm loads are safe with them, since it operates at similar pressures.
This all would be less of a problem if Remington made this info a bit easier to find. I made the discovery with the 6 1/2s just wandering around the internet. I go home & sure enough, fine print.
In my ignorance, I believed that when a primer is designated "Small Rifle" it should not be a huge leap of faith to assume that would include .223.
This of explains why they were the only small rifle primers available that day. In my innocence, I just assumed that it was because Remingtons are typically more expensive then their competition.
Note: the warnings are from the Midway USA site.