It is being blown down the hole in the valve body where the bb's are fed. We are bringing a new smooth bore high quality barrel to the table soon so keep looking for posts here about it if you can't get in touch with Jim C. It will just take longer for you to receive it. Sergey sells his boards for less than I do. I also include a stick on template to show you exactly where to drill your housing as well as a few other things including guidance if you need it. I keep them on hand ready to ship priority. You can buy the boards, and mod chips from Sergey, or me. The 4K board does work with the 30 round mag with a stiffer spring. There is a good chance you will damage your valve. It is not currently recommended to use the that shoots 4K RPM with the Blackbird mag. I will attach a video that explains how both of them work. There are currently two versions available. The other way is to replace the stock board with Sergey's Board.

This changes your rate of fire settings to 600, 900, and 1200 rounds per minute. The Bumblebee will need a stock Drozd, or Blackbird board for the chip. You can replace the stock chip on the circuit board with a full auto chip. There are a few different ways to convert the bird to shoot full auto that works on both of your guns. I can't recommend a trustworthy source for these fittings at the moment. You will need a special fitting to either directly, or remotely connect a paintball tank. If you want to go full auto you are going to want to ditch the Co2, and move to high pressure air like paint baller's use. You can get up to 4000 rounds per minute with the 30 round mag.

With a few mods using the Blackbird mag you can shoot up to 2000 rounds per minute full auto. If you have an extra 30 round mag I would keep it also. If I were you I would keep the Blackbird just because of the magazine. These guns are no longer being imported into the US, and Canada because of sanctions.

Air tank for drozd blackbird