MH WASH,
Are the Laser Cast Bullets gaschecked, plain base, or bevel base bullets? Do you have any idea as to the hardness of these bullets? I suspect they are lubed from the factory?
1400 fps is moving right along for cast bullets in a 44 Magnum. I'm not saying it isn't O.K., but that is "truckin'" for cast bullets unless they might be gaschecked.
I shoot gaschecked bullets in my Redhawk at close to 1300 fps and leading is minimal, yet some does occur. It is usually just minor gray streaking toward the end of the barrel. I shoot a plain base bullet--RCBS 44-250-K bullet at around 1000 fps and I do get some lead just in front of the forcing cone with this bullet cast from wheel weights. Accuracy is good though. Bevel-based bullets, quite simply, are a disaster in my handguns. Leading has always been terrible with this style of bullet...Period. I guess that is one of the reasons I started to cast my own bullets.
You might try slowing them down a bit to see if the leading decreases somewhat. Cast bullets are great when they work properly, but when they don't...OH BOY...........Good-luck...BCB