Kits are pricey. I don’t care if it turns into a frankenbuild. I have an AK74 side folder rear trunnion but would need to cut for the latch and button. Other than the bullet guide is there anything that says I can’t go with a different caliber?  I already have a 104 UR and would like to try something different for he sake of being different. Or should I just piece together 74 parts as cheap as possible and do a fixed stock AK-74?  It bothers me having a receiver around and no plans for it.

You can do 5.45 or 5.56 with an unmodified 74 receiver and front trunnion. For 5.56 you would want a barrel from AK Builder and use Polish or Bulgarian mags.

Afaik .300BO would work fine as well but barrel options are very limited.

If you wanted to switch to 7.62x39 the mag well cut and ejector will need to be modified.

Could I rock any 5.56 based case cartridge as long as the COAL is the same and bullet profile not too far off?  Something like 6x45mm?

Since it's based on the 223 case you should be able to.

In theory

I don't know if you would have feed issues. The AK-74 bullet guide works for both 5.45 and 5.56 since the bullets are similar diameter.

Also the 5.56 AK mags I have seen have a narrow cavity at the front that may not work with a larger diameter bullet. They are not a uniform width like AR mags. 6mm probably fine but can't guarantee it.

5.56 is overall the easiest caliber conversion for AK-74 parts. Almost nothing needs to be modified other than mags and the bolt - in my experience the extractor needs to be modified a little bit to get a better bite on the 5.56 case rim since it's a bit smaller than 5.45. Without this step the case can potentially fall out of the bolt or damage the ejector.

I have been kind of in the same boat but I don't actually have a receiver yet. I want a 74 bad but the fucking kits are getting impossible to source, and what is out there is now over 1k on the low end and around 2k for a better one.

I really wanted to do a 74 Krink but I really don't see any kits being available anytime soon

Yeah you missed the boat almost 10 years.

I ordered a few Bulg 74 kits around 2011-2012 for $120 ea. At the time it seemed like nobody wanted them and still wanted to build the various AKM kits. I never bought any of those

Then the Arab spring and the Ukranian conflict really fucked up the rest of the surplus market. If those two events didn't occur I bet we'd still have a lot of kits coming in.

Oh I was there during those times. But I didn’t buy any extra and just got this receiver recently (gift).

This is a really interesting discussion.

I have a 74 and 74S that I was thinking of selling because I want to consolidate calibers.  

If I’m understanding this correctly, a rebarrel, some extractor work, and new mags are all I need to convert them to 5.56?

Honestly that would be very nice.  

Yes it's a pretty straight forward conversion. There is lots of info on building 5.56 AK-74 kits.

- Nitride 5.56 74 barrel from AK Builder
- Use 1/16" (.0625") drill bit for gas port, same as a carbine length AR. Using same port size as 5.45 will overgass.
- Polish Beryl (surplus or WBP) or C10 mags
- Extractor mod

Some don't mod the extractor but I did for two reasons. 1) the 5.56 rim is a smidge smaller than 5.45 and can fall out of the bolt if held upside down. 2) the ejector may not make full contact with the 5.56 rim on the 5.45 bolt

If you remove the extractor and file a bit of material off of the inner flat stop surface (on the extractor not the bolt - extractor is easy to replace), the extractor will pivot further into the bolt face. This solves both issues by putting a tighter grip on the rim, and pushing the rim towards the ejector slot, guaranteeing full contact with the rim during ejection.

I just pulled the bolt out of my Saiga .223 for comparison and filed on the extractor for the 5.45 bolt until when installed it held the 5.56 rim with the same amount of tension as the Saiga. You should be able to rotate the case with minimal resistance but it should not wiggle around when the extractor is engaged.

I also followed the headspace set procedure in the Galil armorer's manual and used Forster GO/NOGO gauges. The Galil spec is basically headspace on GO + mild thumb pressure on carrier to close a stripped bolt on GO, something like 30 in-lb

I've shot mine a lot, never had a feed or ejection malf, and the AK Builder barrel is very accurate and seems to be holding up well

Attached File

I built a 5.56 AK using Bulgarian 74 parts. Found a barreled receiver on GB for like $200 about 4 or so years ago. Decided it was cheaper to use 74 parts. Worked like a champ.

disregard the airsoft GP-30

Hell no I have thought of buying an airsoft GP30 just to freak out people at the range

@nictra  galil mag?

yes sir. It was a reject receiver from some manufacturer (I don;t recall which one). I think they milled out the mag well too much. My Bulgarian 556 mags didn't work, but my Galil mags worked just fine. 5 more rounds anyway, so I was ok with this.


ETA, can't lie, that airsoft GP-30 is pretty sick. Really wish we could have em, even if they were only in chalk round caliber.

unless I'm not reading what you're saying that's a barreled Saiga .223 receiver. the magwell in the receiver and trunnion is AKM dimension so most of the more common 5.56 AK mags don't work without mods to either rifle or mags.

100% correct