I like to use a chop saw with an ulrafine blade; at least 80 carbide teeth. I have several and none of them have any jigs or attachments. The most basic installation is when I'm maintaining the original pitch. I use a vernier caliper to scribe a 2" line parallel to the original butt and make a single wrap of electrical tape. The tape touches the 2" scribeline but I curve it around the heel, toe and backside so the blade will cut through the tape everywhere except for the first contact. I stretch the tape very tightly and massage it thoroughly to ensure maximum adhesion.
I use a scrap board long enough (30") to support the entire stock and I start by putting the comb tight against the fence with the blade away from the butt.
I swing the blade in to contact both heel and toe and lock it at the right pitch. This works well for preserving the original pitch when cutting a curved butt. The small gap you see is because the blade is perpendicular to the table but the butt is not.
Assuming the original butt was cut squarely, I can shim up the head of the stock with 3X5 cards until the butt makes full contact with the blade, assuring me of making a perpendicular cut. If the stock had been cut poorly before, I can make a square cut by finding the height of the shim mathematically. I can use calipers to measure the widest part of the butt, subtract the width of the head, divide by 2 and get the thickness of the card stack required for a square cut.
When I have any chipping, it's usually attributable to a Remington Imron finish or some miracle epoxy. Every new pad gets a light kiss on the belt sander to flatten it. In my earliest attempts I thought there must be some secret to getting the pads to conform to the wood. I tried heating them to soften them, even sandwiching them between 2 boards overnight with 3-4 bags of lead shot on top.
Finally, I realized how simple it is to sand them flat. You can see how little was removed from this one; it wasn't even necessary for the belt to touch the center.
Sometimes it's possible to eliminate a very tiny chip out in the finish by sanding the butt on the table of the belt sander. I NEVER turn the power on. I push the heel the length of the table with both hands; then draw the toe back the length of the table.
I do that for several passes, then turn it around and push the toe/pull the heel.I'm extremely careful not to rock the stock.
I try not to press my luck; maybe a dozen passes total, frequently checking to see I have a flush fit.
These pics are not of an actual installation, but just as illustration.
