The pins should be cut to length & aprox. 1/64" less than flush on each side. The pins in the rifle are not to catch you eye as you admire the rifle from muzzle to butt, but rather all features & components of the rifle should flow together.
Both sides side of the pins should be slightly rounded. The pins go in from right to left & are removed just the opposite, thus the pin going in made the opening OK and will come back out OK. If the edges are flat there is a good possibility of the pin catching wood & ripping out a sliver. If this should happen, take the pin on out, get some glue & imediately glue it back in before it gets lost.
On removing a pin from a gun that is finished, I always take an exacto knife & carefully trim the hole ever so slightly as to keep the pin from catching coming out.
Also I will mention, the pin holes in the tennons should be slotted parallel to the barrel in the rifle, not just round holes. The pins should go into the stock & thru the barrel wasily, as it is just holeing the wood to the barrel & no stress should be on them.
When the rifle is completely finished & the finish is dry, I usually take some brown or neutral paste wax & put just a tad of it on each pin & work it into the pin hole edges. & seal the pin in.
Custom Muzzleloaders & Custom Knives