While I don't claim to be an AK74 expert over the years I have picked up some working knowledge and wanted to put down a quick primer here. I have always considered myself an amateur AK owner and enthusiast, and my opinions are still written from that perspective. There are many many enthusiasts who have considerably more knowledge than I do, and this page is an acknowledgement of so many people's work.
Please be sure to check out the absolute best reference on AK rifles which covers this subject in amazing detail: Avtomats In Action AK 74 Variants
Also you can download and review the extremely
parts and components
Ekie, Tantal and many others have contributed to creating an incredible reference on AKs. It is a site for the true AK collector and has detail that is invaluable for clone builds, as well as show casing the incredible talent as contributors build amazing replica's. There is no better AK reference site
Fullsize standard AK74's are generally split into
3 era's of major production patterns and I will
provide some details here as it relates to my builds.
To be clear however, this is just touching on the
topic and is really just a quick review of the
highlights of each era.
Mid: 1986 to 1990
Service AK74M rifles are all folding stock with pistol grip plates, 5.5mm folding hardware and have a side rail optic mount installed standard as part of the M (Modernizirovanniy) designation. Previously called AK74 (fixed stock, no rail), AK74N (fixed stock with side rail), AKS74 (folding stock, no side rail) or AKS74N (folding stock with side rail mount), the 90s era cumulative production improvements resulted in the rifle simply being called the AK74M.
There are training rifles which have the black polymer furniture and 74M features but are fixed stock, however these are not in front line service as I understand it.
There are also 4 main variants of the AK74 pattern rifle:
AKS74U (AKSU) (Commonly called Krinkov in the US, but no one knows why)
Check the Rifles
section for more details
If you are considering modifying a fixed stock SLR
or SGL rifle to be period correct the simple guideline
is to use Bulgarian parts for the SLR series and
Russian parts for the SGL (and Vepr) series.
Also of note is that the Bulgarians never modernized their original Russian supplied AK74 tooling and so the current production SLR series are actually very close to 70's and 80s production rifles.
Muzzle Device Patterns:
Top AK74M long collar (In service 1990+)
Middle: 1988 Faceted (1986-1990ish)
Bottom: Early short collar (1974-1985ish)
Both Russian and Bulgarian are 24x1.5R,
vs AKM 14x1L
Folding Stock Trunnions:
Top: Modern 5.5mm with military hinge pin (In
Middle Modern 5.5mm with civilian hinge pin
Bottom: 4.5mm (Russian 1974-1990, Bulgarian 1974 to present)
The difference in hinge pins is mostly cosmetic but military pins are solid and civilian pins have a smaller middle diameter to accommodate the government mandated linkage that prevents the rifle from firing with the stock folded
The AK74M switched to a different stock angle of 4
degrees instead of the older 6 degrees. See below for
ThirtyCal's photo, who is an accomplished
builder, and is also featured on Avtomats
in Action - AK103. His AK103 build is amazing
and his attention to detail is one of the best in the
It is not easy to adapt a 4.5mm trunnion to the 5.5mm stocks and vice versa, so if you are considering a folding stock build it is best to start with the period correct hardware
AK Front Trunnion Rivet Pattern
Russian AK74M rifles switched to 3 rivets in the 90s (The large 3rd rivet is a wear rivet to assist the bolt when it locks into battery)
Russian pre 90's and all Bulgarian rifles use the older 2 trunnion rivet pattern
Top and Middle: Russian SGL31
Bottom: Bulgarian SLR105
Side rail patterns are different as well as you
can see above
Furniture is also different for the 3 eras:
Russian laminate for the early pattern rifles, plum for the mid series and black polymer for the modern rifles
Note that Bulgaria did not actually manufacture plum furniture, so what is called Bulgarian plum is actually Soviet made. You will often see the iconic Russian silver proof marks on 'Bulgarian' furniture
K-Var US made plum furniture is also a different composition and color. Very good quality parts which are also 922r compliant, but not a direct color match.
Top: K-Var US
Bottom US Black Poly (NATO length)
There are 4 Russian AK74 magazine patterns:
(Photo courtesy of Avtomats In Action)
Example of True Black modern magazines (top)
compared to early and late plum (bottom)
Here you can see the plum follower on the left and the true black on the right. Late plum magazines often look black depending on the lighting conditions. Always ask to see a good photo of the follower which will help determine if it's a plum mag or an actual true black