[7.62x39]

There is always a lot of discussion concerning lower rails.
One of the topics is the difference between the two different styles.

My opinion is that if you do not have dimples in your receiver, you need the OE style rails with the lips to stabilize the mag.
The OE style is also usually thicker, meaning less problems with a beat up ejector.

 

[7.62x39]

These are undrilled so you can locate them wherever necessary for your particular build, they also have the hump for the axis pin

They are available from K-Var.

Part numbers AK74S and AK75

http://www.k-var.com/shop/home.php?cat=278

 

[7.62x39]

AK-Builder now has copies of the factory style rails.

 

[7.62x39]

Top= Bulgarian OE rails
Middle= AK-Builder OE clone
Bottom= Tapco type