In switching back and forth from the standard FX shroud to the FX integrated barrel tuner I was surprised to see a marked improvement in extreme spread with the integrated barrel tuner. Spreads of 8 to 10 to sometimes even 12 fps with the standard shroud dropped to 2-4 fps with the tuner in place. Measured in 10-12 shot groups. Has anyone else experienced this? The barrel tuner results were good as well - 3/8” group at 45 yards with a light breeze. Shooting an FX Impact M3, .25 caliber, 600mm barrel, JSB King Heavy pellets, 863 fps average. Macro 16, Micro 3-1/2, Valve at 4, first reg 150, second reg 108.