Home Forums Hunting & Shooting AR and Tactical Rifles AK Pattern Variations

What's the best way to tell an AK pattern? I have a 2006/2007 Vector Arms AKM, supposedly made with a U.S. receiver and Bulgarian parts kit. Vector Arms was a company from Salt Lake City, Utah. The receiver is marked "Mod: NDS-1" and "DC Industries Inc., St. Paul, Minnesota". It has holes in the gas tube, but I assumed it was a Bulgarian pattern, or at least not a Yugo, Century, etc. I'm not even sure I'm using "pattern" correctly in this context, but I hope I'm being clear enough. I was told this isn't a "regular pattern AK", and now I'm curious. Can anyone shed some light?

Vector did a lot of different AK pattern rifles built from surplus parts kits on US receivers.
I have a Polish stamped underfolder and a Bulgarian Milled underfolder.
Most likely its a Bulgarian milled kit (thicker barrel, 45deg gas block, vent holes and milled style front sight base) built on a stamped receiver.
Any markings on the trunnion?

Thanks, JBhunter45. If this rifle's trunnion is marked, it's covered by the receiver. Would what Vector did be called pattern-mixing, or does pattern depend primarily on front trunnion? My original question came up when a gunsmith was installing a side rail plate on the rifle. He had some alignment difficulties while using a standard(?) AKM rail plate and when talking about it with fellow gun scholars was told about the pattern difference. Long story a bit shorter, he thinks the side plate will work, but i'm curious whether a plate for a specific pattern would work better. And i feel a bit vulnerable not knowing exactly what the rifle is.

Call vector arms and talk to them.
They can probably run the serial# and tell ya what ya need to know about the rifle.

Thanks, renegade50. Not a bad idea. I overlooked that since Vector Arms changed hands once or twice, but i'll give it a shot.

To get a milled barrel in a stamped receiver trunnion the barrel chamber area needs turned down from 23 to 22mm.
Installing the rail has more to do with the rear trunnion rivet pattern. Different countries used pattern variations depending on age and what factory made them.
No clue as to what Vector might have used. The rear milled trunnion is part of the receiver, so they had to replace it to build on the NDS.

Thanks, JBhunter45. I just googled NDS-1 for the first time and tons of information popped up. I feel kinda silly for only trying that now. Seems like the best path to go down for now, until i hear from Vector Arms, or run into a fellow customer.