The barrel is rifled steel and extremely thick and rugged for an airgun.
The price of the Drozd is much higher than typical "department store" airguns, partly due to the use of the higher quality components and increased durability. The gun is manufactured by a company that also manufactures and designs military firearms (best known for their WWII production of the Tokarev TT-33 and M1895 Nagant revolver), and many of the parts are thus "over engineered" with military-style durability. The quality of the gun is high, with the main functional components being made from firearms quality steel and the plastic parts ( trigger, main receiver housings, buttstock, lower magazine cover) being made from firearms quality fiber reinforced polymers. Such modifications include aftermarket/third-party and user-community alterations and upgrades such as "mod boards" that can increase the rate of fire up to 2000 rounds per minute and provide true fully automatic operation, adapters to use external propellant sources (such as 20 oz paintball CO 2 tanks or HPA scuba tanks), dye kits to change the color (commonly RIT fabric dye is used), and longer barrels (higher velocity).
It is popular with both casual target shooters and airgun enthusiasts it is excellent out of the box plus offers customization options and upgrades. It is a riot to shred cans with, and commit other senseless acts of destruction (in the usual responsible manner, of course).The MP661K is best known for being one of the few (if only) select-fire BB guns and can fire single, three-round, and six-round bursts - although in some markets, such as the United Kingdom, only semi-auto is available. I haven't had it out in ages, but it is a really cool gun, considered as a piece of hardware. I don't consider it suitable for hunting (it would work on sparrows), and after the novelty wears off it just sort of sits around. You can up the velocity, vary the rates of fire and burst length up to true full-auto, and pimp it out with all sorts of tactical accessories. There are many mods, and entire sites, devoted to the Drozd. I never had a jam with steel BBs and haven't tried lead. They are apparently more powerful and accurate, as you would expect, but the lead deforms too much to feed as reliably. The Drozd paradox is that steel BBs wear out the barrels- but lead balls tend to jam them. Replacement stuff can get 'em up in the 700s, I guess. I forgot the velocities but the stock versions are around 500 fps or so. They normally include a speed loader for the BBs which is a godsend. They go through a ton of CO2 and BBs in a hurry. I thought the neighbors would call the cops for sure (they didn't, but I stopped). The first time I shot it, from inside the house out the back door, I freaked out. They are very accurate, considering they are shooting BBs. Stock, they have selectable rates of fire and burst length, plus single shot. They are not lightweight, but feel like real firearms. They are an extremely well-made BB machine-gun.
They are amazing machines, if rather useless. I have one that I got used, without sights but with the other accessories.