Hi there, I have a .22 Brocock Sniper HR Magnum. The HR indicates it's regulated with a HUMA regulator and the magnum indicates that it is a higher power model. With JSB Monsters (25.4 grain) it's a 45-46 fpe gun shooting these pellets right around 900 fps. The barrel on this model is a LW polygonal version. While the barrel is shrouded, I would not call it backyard friendly at its normal power level. I also refer to this gun as a one-trick-pony. It shoots these monsters very well, but has not shot any other pellet well. Ironically, the next best shooting pellet are the cheap crosman hollow point 14 grainers shot at low power. The gun has a "power adjuster" which is a simple air flow restrictor.
While it's nice that the gun has an externally adjustable regulator, you can only adjust it UP when the gun is pressurized. If you try to adjust it down, you will damage the regulator. You need to degass the gun to lower the reg pressure. The hammer spring is also adjustable but the stock needs to be removed to do so (which is easy).
I like the size of the gun, it shoulders VERY nicely and is exceptionally well finished.
I recently acquired a Kalibrgun Cricket II in the same caliber and the Brocock is sitting. I will be putting this sniper up for sale and would be glad to give you further details if you're interested.
Here's are two 5-shot groups comparing Monsters to NSA slugs at 50 yards: