Thread: Zastava 7.62x39 Restoration

Ok... so Im an idiot.. in a moment of distraction I have used the wrong powder data!

I knew something wasnt right, many years ago I had a 16" AK47 that I loaded for that had no problems getting over 2400fps with 2207. I kept asking myself, what has changed? 1/2 an inch less barrel length surely wasnt the issue.

Nope, I had used Hodgdons load data which I had saved as a shortcut on my phone knowing that ADI AR2207 is the same powder re-labeled for Hodgdon as H4198.
However at a glance I selected IMR 4198 which has the same numbers but different burn rates. The listed max charge for the IMR was 24gr which seamed light when I was testing.
After checking ADI's website I realised what Id done.

So with a new found max charge of 26.5gr I went back to the chrono and settled on a charge of 25.5gr @2350fps.
26gr only gained 10fps so the 2207 is getting a full burn at about that in my short barrel.






Can anyone explain to me why IMR shares the sane numbers as many of the ADI/Hodgdon powders but have very different load data?