My understanding is that their Berdan Primed steel cases are produced by an East European partner.
I have shot plenty (500+) of TulAmmo 55gr which are Boxer primed, with zero function failures or evidence of abnormal wear to my Stag action.
Further, the Boxer priming tempted me to try reloading some.
Using my 75gr match load recipe (23.5gr Varget, HDY 75gr HPBTM, CCI BR-4) the load performs identical to my brass case (PPU brass) version of the same load, and has stood up to 5 reloads so far. The polymer case coating has slightly dulled, the mouth interiors respond well to inside neck chamfering (eliminates bullet shaving) and the primer pockets seem to be resisting expansion as well or better than brass cases.
I have been advised to avoid hot loads with such cases, and have followed this advice. The above load, like the original TulAmmo 55gr load, is on the milder side; which suits me fine because my shooting distances are limited to 250yd and will likely never exceed 300yd altogether.
BTW, my Stag 6 Super Varminter shoots even the cheap TulAmmo 55gr quite nicely.
Some of the local Wal-Marts are selling sealed spamcans containing 500rd of 55gr Berdan primed steelcase ball (in 25 20rd standard TulAmmo packaging) for $119.95 plus tax, which makes these reloadable cartridges comparable in cost to regular brass cases alone.
Greg
PS, one of my 'next' reloading projects is to pull down the 55gr TulAmmo ball ammo in large quantity, then do individual load development with the components for several of my .223 rifles. Agreed, the components are not top notch, but with proper load development, accuracy equaling or even exceeding good factory ammunition's might be achieved. Experience with spamcan 7.62x54R strongly suggests the possibility.
I have acquired a new Hornady automatic powder dispenser to ease the task of rebuilding ammo in bulk to new specs. It's not infallible, but it's pretty darned close (it looks like when it finishes dispensing a charge, it compares it to the set point, and accepts it if it is within .1gr of it), dispenses the powder at least as accurately as good factory ammo, and faster than I need it, even when I'm loading in progressive mode. Accurate to within .1gr is way good enough for me, considering that the rest of the components are economy-plus items,.