Hey everyone,

I’m looking into adapting the Plastikinov v4 from 5.45x39 to 5.56 NATO. Good news: apparently the mag lockup is identical between calibers, so only the follower needs modification.

According to people familiar with the design, it “shouldn’t be too hard looking at cartridge specs” to adapt the files.

What I need to research:

  • Follower geometry differences between 5.45x39 and 5.56 NATO magazines
  • Taper differences: 5.56 is straighter than 5.45x39
  • Barrel/bolt specs: What changes beyond the obvious bore diameter?
  • Trunnion and bolt carrier might be identical between calibers
  • Commercial 5.56 AK mags to test-fit geometry (Galil, M85, SLR-106)

Has anyone here done work converting AK receiver files between these calibers? Any gotchas I should know about beyond the follower and barrel?

Alternative: Should I just buy a ZPAP M85 and call it a day?

Thanks!

  • MR.BLICCY :)English
    3·
    1 day ago

    2nd to this there a reasonable way to convert to 300blk instead of 556 if anyone knows, I am completely unfamiliar wit Ak platform

    • EngineerOPEnglish
      2·
      1 day ago

      I’m interested in 300blk also… 😍

  • PhilMeGroinEnglish
    3·
    1 day ago

    Many commercial 5.56 ak’s have had issues due to manufacturers using 5.45 carriers/barrels. Very few combos of 5.56 parts exist with good function and accuracy. Carriers are not interchangeable between many variables (manufacturer/generation/factory) due to bolt lug dimensions/headspacing complications during break in/parts lapping. If you want a 5.56 ak, dyor and buy one, or a parts kit of one if you’re intent on printing the receiver. Of note, most trunnions for both are indeed 23mm journals (ak-101 etc)