from reading, i believe i saw that the stock barrel only fills half of the outer?
Would you recommend the 380 mm barrel to fill that outer barrel?

My mag that came with the gun leaked, but the bottom screw was loose, so after that was fixed, it works like a charm. I'm planning on getting the 30rds soon though.

That stock barrel is plenty long believe it or not. All I would recommend is installing a RA-TECH hop up rubber. You will notice a huge accuracy increase with just the rubber, and your gun will shoot very far.

Well, it is only half the length of the outer barrel, but it IS plenty accurate stock. I would also have to recommend the RA tech rubber, i use it with the full length RAT inner barrel and the accuracy is astounding. Just need a way to get the FPS down!

No no I meant that the half length inner barrel is plenty long for the distance the gun is shooting, not that it's longer than half length, just poor wording on my part lol

No, because if you buy the full length RATECH tightbore (or similar) you'll be shooting around 600fps.

If you get the full sized inner barrel with the rat hopup you will be fine if you use duster in the summer. once it gets colder you can safely switch to propane.

ok, thanks for the help guys. I will buy the ra tech hop up then, and leave the barrel as is. I only ask as I was watching a video on ra techs site where the 380 barrel was much more tight groupings.
Has anyone installed the npas for it? I saw on the same video at ra tech, they were saying its difficult to install

There is no NPAS for the KJ 10/22.

I have the RA tightbore, shoots 480 consistantly on propane. Yours must be way hotter than mine.

Are you testing in winter temperatures? Stock mine shoots 430-440fps with 0.20's. Using 0.28's, it shoots 350fps, or 480fps equivalent on 0.28's

Our chrono result on the weekend was approx. 450-460 on propane with 0.28s. I only installed RA Tech hop up and TB.

Yeah, so that's 530-540fps on 0.20's.

I have the RA m1 carbine kit, tested indoors, 480 on .20g.

Had 478 fps on .28 at 30 celcius last years...

I wonder why RA don't make a npas for it :(