Please help ID barrel threads

[Bogey Fett]

Mystery barrels from an eBay auction, I'm guessing either A5 or Autococker.
CP barrel is 21.6mm at the threads, 20.3mm shank. Brass barrel is 21.8mm at the threads, 19.9mm shank.

Thanks!

[Carp]

www.docsmachine.com/tech/barrelguide.html

Autococker


A5

[Meleager7]

so shiny!

[Ecapnation]

Both are "a5" but the brass one could be for a prolite

[Bogey Fett]

so shiny!

Right? Spiral ported brass gives me the fizz!

[Bogey Fett]

Both are "a5" but the brass one could be for a prolite

Will an A5 barrel adapter work for either/or?

[Ecapnation]

Yes/no some early prolite barrels are stepped to let the bolt enter the barrel

[Bogey Fett]

Ecapnation I can't figure out how to like or reply to a comment but you got it, the step is hard to see but I can feel it with my booger hook. Thanks.