Thanks man! Finally, somebody here who actually owns one, hehe. I thought I was gonna be the first one to test these. I waited as long as I could for a reply,, but I had to go ahead and snag one, did not want to miss out again. Anyway, it should be delivered to me on Thursday, so there is no need to go to all the trouble to measure now, but I certainly do appreciate it, sir!!
AK-Builder has been out of these for weeks, but I luckily checked one last time with them again Monday morning and noticed they showed a small batch (6) were actually in stock, of the chrome lined variety, and at a very good price. So I went ahead and bought one. Just in time since I was about to pull the trigger on an overpriced unit listed on GB which was at least $100 over what Curtis sells the same barrel for.
I should know by tomorrow afternoon how well it will work with my trunnion and other parts. Did yours seem to fit well with your parts, or have you tried any of them yet?
Well, I'm impressed with this new AK-Builder barrel. I'm glad I was able to snag this one sinceI already sold all my original Russian RPK barrels. It will allow me to complete my last 1976-dated Russian RPK kit. These are the desirable chrome lined version, BTW, and with this US barrel and a US receiver it will make it easy to meet US parts count regs with only a trigger set and piston while keeping all the evil Soviet furniture. I highly recommend these, they have been out of stock for months but they had 6 in queue when I checked Monday.
On first inspection, it's obvious that it's very nicely machined, and all my journals check out GTG. They either fit my parts spot on (with the correct amount of interference), or will only need just a bit of polishing to do so. Most important of all there are no "helicopters", hehe. Also, my basically new condition Russian bipod fits super snug on it's journal, just like a factory barrel and bipod in new condition should fit. Rotates super smooth with zero wobble. Lower handguard retainer also fits great and slides onto it's journal smoothly and the retaining lever rotates in place with no snagging.
So far I'm just going by my past experience with barrel attachments fitments (not from exact measurements) but from feel, and everything seems to have the right 'bite'. The gas block was spot on (it just barely starts on by heavy hand pressure, by about an 1/8 inch). The front sight base is a little tighter (I can't get it to stay put in one place even though it tries to start), while the cleaning rod ring will likely need some polishing before it will ever start. The main thing, the barrel journal, thankfully won't start on by any amount of hand pressure, so IMO it won't need any knurling. I did measure the barrel socket and journal to be sure, and from my cheap calipers (and bad eyes) it looks to measure 23.08 at the chamber end while my trunnion socket seems to be right at 23mm exactly. To me that sounds just about right, how about you guys? In any case, these types of fitments are exactly what I'd expect from an average, usable in-spec factory made barrel, so needless to say I am very happy with the new purchase.
Plus, the chrome lining on these looks good and the muzzle threads, chamfers, tooling, ramps, steps, and lathe lines all look great to me. Looks very much factory, to be honest. All it is missing is journal size numbering, Soviet forging symbols and codes stamped onto it, then a nice squid ink paint job to make it a good fake, hehe.
I guess the only down thing (or inconvenience) I can think to nitpick about is that the gas vent is not drilled. It does have all other things done to it, i.e. fully machined side slots (and lever shaft groove) for the lower handguard retainer, as well as the extractor cut on the face of chamber and the muzzle threads which look really well done, BTW. There are no barrel pin (or other retaining pin) grooves, which is how it should be and a very good thing.