ak2m4

cylinder vents sounds right, as other said chop and change the chamber and/or the nozzle

What's the cylinder type, and what's the spring if you happen to know?

Some good solutions. Generally 1st thing you need to do is remove it from the AEG and give it a thorough clean. Some barrels have tiny burrs left inside that are impossible to see without a decent borescope. I've seen tiny machining marks left over in the last 30mm that give the BB a tiny spin. If you're near me in Kent (River) leave it with me and I'll run my borescope down it for you.

31K's Long and Short should arrive next week

Hi and welcome. Kent here. Congratulations for not calling UKARA a "license" 🙂

What happens if he just puts the stock inner barrel back in? This the SRS barrel that has a 2-stage barrel right? If you mate wants he can send the barrel to me and I'll do a borescope inspection of it

Could be the Rhop setup, could also be a slight fault in the inner barrel. Personally I'd get rid of the rhop to start and test a few buckings out. Then move onto the inner barrel. Is the barrel stock? How long is it?

Yep all lengths in AEG. I'm just waiting on the 2nd sample to arrive, hopefully end of next week. They sent the 1st sample to me couple of weeks ago but it didn't have the internal polishing. I'll post up some video of it. Again some interesting stuff with in that you all might find interesting.

2 identical aeg's for testing, one with a 3/4 and other with a closed, same hop, same rubber. I imagine many people will disagree but it's just my observation. Maybe it's down to the super tightness of the barrels I was testing, most around 6.01 +/- 0.01. I didn't get too technical for linear relationships and curves, if it flies straight and long I'm happy. I should have 6.03 / 6.04 stock in soon so will be interesting to see what they're like. Ultimately the shorter barrels just seemed to give me a lot less grief. When testing when I come across ones which I'm not happy with I just put them to one side, I bore-scope them to see what might cause the curve but I can never find what it is. I've been refining the process over the past 6 months, I'm a little sick of it tbh as it's a lot of extra work in deburring and polishing. I won't be doing this when the new barrels come in thankfully.

Would be easy enough to tell. not only the main controller but also the speed controller (if it has one) which sits underneath the ESC

you read right 🙂 260 to 300 seemed the sweet spot. Of course this is my own testing, the longer ones still performed well but just not as good as the shorter ones.

Yes it's highly possible. I also found that having the last 3 or 4 inches polished to a high degree can make big improvement for any lengths.

this is just from my own research in my own particular case. I've got hundreds of identical polished new barrels, polished to RA 0.5, all different lengths from 128 to 500 - same bore size. Have tested about 400 so far and one clear observation is that the shorter ones are more accurate.

@GiantKiwi you said Warhead are a rebrand of Chaoli, yet Warhead were released way ahead of Chaoli's brushless offering. Have you opened both up to take a look?

Most of the spring guides I've seen use the standard airsoft thrust bearing same as the one used on the piston head. I have plenty spare if you want some however do your spring guides have the function to unscrew to allow a bearing to fit?