i hardness checked the 3 stubbs of a demilled bulgarian ak-74 receiver at work the other day...and, i was amazed at the results.

i performed approximately 12-15 checks in various areas of the front, rear and floor receiver sections that i romoved from a friend's kit.

no matter where i checked, the receiver parts gave consistant readings in the 28 to 31 rockwell "c" scale.

what this means is that the receiver is consistantly "hard enough" from front to rear, top to bottom.

what can be deduced from these results is that the receiver is made from a steel that is roughly equivalent to our 4140 pre-heat treat steel (1mm/.039" sheet would deform if heat treated after the receiver was die formed and punched).

how clever of those bulgarians!

this is the hardest receiver i have yet tested, beating out the fairly hard hesse, soft russian junkers, and soft but induction hardened itm/oow receivers by healthy margins.

now, this has me wanting a factory bulgarian kalashnikov even more!

agreed, shortfal. the itm/oow receiver is soft as butter. the areas that show evidence of induction hardening are the hammer/trigger pivot pin holes and the ejector tab. as shortfal said, an expirienced metalsmith can 'feel' the difference in the receivers. the bulgarian is much stiffer and requires noticably more fore to deform.

the hesse receiver that i tested two years ago showed a hardened ejector tab, and rockwell readings in the low 20's. not bad...and it was authentic looking.

the hesse also has the propper/authentic "y" and "x" reinforcement indentations at the pivot holes. the itm/oow does not.


if i were going to build an ak-74 tomorrow, i would try the more expensive hungarian f.e.g. receiver that globaltrades is selling.

the itm/oow has some dimensional issues that i was not pleased with...nothing catastrophic, but there was no need for it to have been so far out of specification.


all said, these are 'just' kalashnikov's and semi-skilled constructors can easily get the hesse, itm or other receivers to work. as far as durability goes, i think even the soft steel receivers will hold up just fine. this reminds me of the cast vs forged ar receiver arguements. i have a pre-ban cast dpms ar that has been abused since 1993 without falling apart.

imo, the "best" route is to use the hungarian feg rac's that jimmy streetman sells. by the time you've dickerd around with "upgrading" your itm/oow, the feg has paid for itself.

that said, the hesse and itm built guns are NOT junk. they just are not the best option...that's all.

we live. we learn.

for the additional $100 the feg is still top rated in my book. that's all i'm trying to say.

jimbeam, a google search using "globaltrades" will get you to their website.

mbsk01. please...do not attempt to heat treat your reaceiver. it will ruin it.