The pin holes in my GPR measure about .040 inch.
That's a tad larger than 1/32 and actually equates to about 1 mm.
If I was building the gun, I would leave those pins alone. They really don't need to come out because you don't really need to remove the nose cap or the ramrod thimble.
Your task is to lightly sand the wood down so that it matches the shape of the metal nose cap without a step of any kind. The wood should not stand proud of the cap and the cap should not stand proud of the wood.
You will probably end up getting some scratches on the metal nose cap when you do this but try to keep them to a minimum.
To help minimize the scratching you can wrap several layers of masking tape around the metal part.
After the wood matches the nose cap, use some of the black "wet/dry" silicone carbide sandpaper to sand out the scratches on it.
This sandpaper is meant to be used on metal (dry) and the finer grades on painted surfaces (wet).
To remove the scratches you might want to start with some 180 grit and then go to finer grits like 320.
Note: If you intend to brown the steel parts with a slow rust solution like Laurel Mountain Barrel Browning solution, do not go finer in grit size than 320. Actually, 280 grit leaves a surface that browns very nicely. 400 grit can make the surface too smooth to get the browning solution to start to work.
If there is much mismatch between the size of the wood and the size of the metal, do not just sand the area next to the metal.
Done right, the entire area of the wood will be the same size. In other words, don't just chamfer the wood next to the nose cap. Blend its shape at least 1 1/2 inches on the sides while allowing the bottom of the forend to blend down into the area where the ramrod guide disappears into the wood.