.44 Mag loads - high pressure?

[Unclenick]

The reason for that difference is partly alloy. Federal and Remington use alloys close to 80:20 low brass. Winchester uses something closer to military 70:30 cartridge brass. There is some detail in the article, X-ray Spectrometry of Cartridge Brass. That said, you can harden brass considerably by working it, and Remington seems to do more of that than Federal does.

[Sevens]

I think it's a losing bet if we simply judge some by headstamps, especially some of the ATK brands like Federal, Speer and Blazer. Just in Federal all by itself I see radically different brass. and .45 Auto & 9mm are shining examples.

Federal brass in these two chamberings comes in two entirely different styles... one appears to definitely be extruded brass and it has a different head stamp than the stuff we recognize from years back.

I've lately seen a lot of Federal .45 that appears extruded but still runs a large pistol primer, along with all the new Federal brass that definitely runs the small pistol primer, but yet I still see the classic Federal brass with an entirely different lettered font and case head appearance, running the classic large pistol primer.

It would be a tough bet to hope or assume they have the same physical make-up when they literally appear nothing whatsoever alike. And all with the same name on them. Pretty sure Federal spits branded commercial ammo out of at least two different physical plants hundreds of miles apart also.

All I ever attempt to do is give myself the best chance at consistency. For the most part, I don't believe it's a safety issue, it's just attempting to line things up in my favor for repeatability. I believe it can be a safety issue in semi-auto rounds where case mouth tension/bullet pull is erratic due to different brass.

[Unclenick]

At the very least, you know a different appearing headstamp was made with different tooling, regardless of process.