Many months ago I started out building a 74 in a .223 caliber. I finally got some of the items out of the back log and had time to work on the beast.

I started with a AK-74 Bulgarian kit from K-VAR and a .223 barrel from them as well too.

If you can do a search in here I posted some info on the trunnion size and dims of the barrels.

If I do this again I will start with a .223 blank and contour it my self. The location of the gas port is .100 inches too far forward. And some of the diameters were too large and needed to be turned down a bit. I set my barrel back and re-chambered. Rechambering is a bitch on a chrome lined barrel. I also silver soldered the FSB .100 forward to comply with all laws.

Everything was pretty simple after fixing the barrel. The 74 bolt works no problem with the .223 dia head.

The 74 mags I'm using are double circle 21's. With a slight lip tweak they feed with out a hiccup.

Personally I would not recommend this conversion to the causal DIY guy. The barrel took a lot of machining to get it to fit right (were talking mill and lathe). If I had some CNC equipment Ill bust out some barrels precontoured. But sadly I don't.

I have been considering an AK project in 300 Whisper and while I have not had a great amunt of time to look at this project folowing is my basic plan of attack...

1.  Start with a PMKMS 7.62x39 kit
2.  Find a 223 Bolt (if possible to use 223 Bolt with PMKMS kit)
3.  Build from new receiver
4.  Have a 300/221 barrel made that matches the PMKMS barrel's profile (1:8 twist for heavy VLDs)
5.  Modify front trunion as necessary to feed 223 (or 300 Whisper in this case)
6.  Work on an adjustable gas block

Based on your experience am I making a mistake even considering this project?

You know. I would start with a 74 kit. I'm not having any problems getting the rounds to feed off the stock 74 ramp.
Getting a mag for your application is going to be the problem. I don't think that there would be enough area in the front of the mag to get the larger bullet in. A 47 mag might work but its angled wrong. Maybe if you can get some .223 bulgy mags and see if the rounds fit.

No your projects is doable! And would be damn cool too..

HMMMM I need to get another flat and a kit... Well maybe after I get my 460 Wby Mag completed.

Well I have a SAR-3 and plenty of the Wenger 223 mags...  I have not loaded one with 300 Whipser ammo yet but I fail to see how that would be much of an issue...  The Wenger mags are real close in size to the AK-47 mags as well so making these fit a standard trunion should be relatively headach free...

I just need to get my other builds done first and get more practice...

I do have a Tantial kit that I could use as a starting point however instead of a PMKMS kit.

Please pass on whatever information you have on converting the 5.45 trunion to 5.56mm.   Couldn't find anything with the search engine.  

Quoted: Please pass on whatever information you have on converting the 5.45 trunion to 5.56mm.   Couldn't find anything with the search engine.

I used the standard 5.45 trunion with bullet guide. All changes were made to the barrel. The barrel was a 23mm and the 5.45 trunion was a 22mm.

Ill dig in teh archive and grab the stuff for the non-paying members..

From the old thread

Ok a real update!!

First the barrel measurments...

.223 bulgarian barrel that k-var sells.           |          Bulgarian AK-74  Barrel 
Location                Inches          Metric         |         Inches         Metric
Journal                  .908              23.06        |          .871               22.17
Rear SB                 .731              18.58        |          .691              17.56     
Gas Block              .593               15.04       |          .591               15.01
Front SB                .572              14.54        |          .570               14.52

 

Link to the old stuff in the archive

archive.ar15.com/forums/topic.html?b=4&f=51&t=68394