Thats because those rifles had the old non up to date manuals. You had to call back then to ask about the max charge with loose powder. They still state that its best used with pellets for a better burn.

when i get home i will be more than happy to show you in the owners manual that it is ok to shoot 150gr loose powder.

What would happen if someone took these 140gr BH209 loads some of you guys shoot and use it with say, a 300 or 350gr projectile in the guns you guys are shooting? Have any of you shot heavy projectiles with that much powder?