I've always used Promtheus 6.03 barrels in my AEGs and have gotten good results with them. Hearing about the benefits of DBC 6.01 tightbores, I was willing to spend the money ($69.92 to be exact) to find out first handed, which barrel is more accurate.
My brand new DBC 6.01 x 455mm AK barrel arrived today.
I have 2 AEGs, a TM M14 and a TM AK47. The AK47 is quite simple to change out the barrel, so it was choosen as the test bed.
I have a nicely broken in Systema bucking with a Big Out H nub in my AK47, so I used it for both tests. I've found Marui .25g BBs to be the most accurate, so I used them for the tests.
First, the chrony results (from a Chrony Alpha).
25 shot average (the AK has a Guarder SP120 spring w/ 12g piston weight):
DBC 6.01 - 385 fps
Promy 6.03 - 390fps
The DBC barrel shot 5 fps slower
I did a preliminary test in my back yard. There is an 8" tree about 90 feet from the back of my house, I shot at it.
With the Prometheus 6.03 barrel, on semi auto, leaning against the door jam in my back door, I can hit the tree, pretty much in the same spot in the middle, every shot. I adjusted the hop up through a range of settings, and could always hit the tree in the middle (except when it was excessive). This is about a 2" maybe 3" grouping at 90 feet.
With the DBC 6.01 barrel, on semi auto, leaning against the door jam in my back door, I couldn't even hit the tree every shot. The grouping was all over the tree, including misses to the left and right; It was inconsistent up and down also. Adjusting the hop up through a range of settings had little effect (except when it was excessive). I spent some time looking for a hop up setting to make the BBs fly straight, no good. I took the barrel out, checked the bucking, hop up, nub etc and reassembled. The second time was exactly the same as the first.
Just for grins, I put a couple of hundred rounds through the 6.01 on full auto, to test for jams. It fired smoothly and did not jam or plunk once.
I had planned on taking it on the field the next time I go, but there is no point doing that.
I've used Systema buckings in Systema, G&P and Marui hop up units. I've used them with G&P, Marui, Madbull and Prometheus barrels. I've used them with standard nubs and with H nubs. Never had a problem. And no, there is nothing wrong with my AEG.
Conclusion a Prometheus 6.03 barrel is night and day better then a DBC 6.01 barrel. I was actually suprised at how poorly the DBC shot. Maybe I got a bad DBC barrel. Maybe they have poor quality control. Maybe they just don't shoot that well. Maybe a different bucking would have worked better. Maybe a meteor will strike the earth and kill us all.
For me and DBC barrels, it's "once bitten, twice shy". It's Prometheus all the way for me and tightbores.
Anyone want to buy a DBC AK barrel cheap?