Can someone tell me the difference between the single and double hook trigger sets? What are the pros/cons of each? And can I install either one in a Bulgy AK-74 5.45mm build?

Thanks

To your first question, the answer is simple. The difference between the two is the number of hooks. Some people believe that the double hook is smoother and more reliable. Personally, since the Russians, Bulgarians, and Polish used the single hook in their latest weapons, I think it's good enough.

As to which one you use, it depends on the receiver you're using. If the receiver is cut for a double hook then you can use either, but if it's cut for a single hook then you'll need to cut the other notch if you want to use double hook.

Schulze

Look at your trigger from underneath. It if has a notch on each side you have a double hook setup. If you just have one notch on one side you have a single hook. I was confused as hell when I first saw that also. Then I asked around on here and then I realized it. DOH!

The AK-47 had two hooks so in case one of the hooks broke the rifle would still function. Well the hooks never broke so one was eliminated when the AK-47 was moderized in 1959 to become the AKM. All the countries in the Soivet Bloc adopted the AKM. The Chinese and Soviets had a falling out over Mao's failed social programs that resulted in millions of Chinese starving to death. The Soviets fearing social unrest in China refused to give Mao the atomic bomb in 1959. Relations were really straned till a split in 1964. Wheather the Soviets refused to give the Chinese the AKM or they didn't want to retool is unknown but they never adopted the AKM but stuck with the double hook trigger of the AK-47.
There really are no pro's or con's of single vs double hook triggers. The reason that the Chinese rifles have a better trigger pull than any other rifle imported to the USA is because of the amount of fitting/polishing on the hammer/trigger contact surfaces not the number of hooks.