Typical cue butt woods have a specific gravity close to unity (1 cu ft of wood weighs almost the same or sometimes slightly more than a cubic ft of water).
But lets go with about 90% of that and round down, calling it 54lbs/cu ft.
Check my math, but that means it takes 2 cu inches of wood = 1 oz, or 1 cu inch per 1/2 oz. Hint: that is pretty close to a 1/2" round hole 5" deep. It gets bad really fast if the hole is only 3/8", or if it is only 5/16" drill for a 3/8"-16 weight bolt. Maple is lighter than typical butt woods, so if the butt is cored, the hole will have to be even deeper to lose that mere 1/2 oz.
Taking a steel 3/8 - 10 joint pin out and replacing it with a G10 3/8-10 will remove about a full ounce. But it will change the balance, you may or may not like that bias Good for LD, maybe less good for break cue.. You can saw some off a steel pin, but it may compromise the joint and threads in the wood parts if you need to take more than 1/8 or 3/16" of each end. If the pin is smaller diameter, the gains are less and the risk goes up. If it has a steel joint collar, change it for aluminum. etc. I am a hobbyist cue maker, only use 3/8-10 joints (& full splice) and am not familiar with Schmelke.
refinishing the butt including a heavy sanding before the new, can sometimes lose a 1/4 or 1/2 oz if you keep the new finish thin.
It's fairly (surprisingly) difficult to remove 1/2 oz in one easy location from a good cue without changing it. (unless of course it already has a weight bolt to be removed)
smt