As regarding Hornady, I've never read of them using Lake City brass, (doesn't mean it might not have happened.) However, I have a good bit of Hornady brass here that is headstamped "Frontier".
Regarding XM193, this from Pew Pew Tactical:
- Federal M vs XM (5.56) and XM193 vs XM85
Learn the confusing differences between Federal’s X and XM designations of their 5.56 ammo, as well as the differences between XM193 and XM855 rounds.
Green Tip M855
Plus ammo recommendations!
Federal 5.56 M193 vs XM193
XM193
In a nutshell, “M” by itself means that it meets military specification (mil-spec) while “XM” means it does not.
But just keep in mind that mil-spec is very stringent and even a small thing out of specification can lead to tons of ammo being rejected.
And overwhelming consensus/review is that XM193 is some fine shooting ammo. But for some sleep-inducing reading pleasure, you can check up the
mil-spec standards of M193 for yourself.
Federal must have gotten so many questions that they put up a site that describes XM193. Emphasis is done by me.
XM193 product is first run, first quality product manufactured at the Lake City Army Ammunition Plant for Federal Cartridges and is made to Federal specifications typical for commercial ammunition.
All XM193 product is the same regardless of the sku or part number. (ie. XM193C is the same as XM193F, XM193CBP and etc … ) The only difference is the package configuation.
Sadly the page is now down (as of 2016) but here is the
link (slow load) where I grabbed a cache of it from 2012 and a screenshot of the cache below.
End quote
(
https://www.pewpewtactical.com/federal-m-vs-xm-556-xm193-vs-xm855/)
Vettepilot