I suppose a better description for the type of dividers used in this case should be cranked rather than bent but I suppose it is how you look at them. The principal of making them is very simple though can be disconcerting at the same time you are making them, it is a method called cut and crack. Firstly, you decide where each bend should emanate from and draw a line at each change of direction point. This line must be at a right angle to the divider bottom, failure to keep to this will result in a case divider that will not sit level on a flat surface. Now just some important does to remember, the one I have just mentioned mark at a right angle and the other is you always with no exception cut along the line on the opposite side of the divider to the direction of the bend lastly cut should be no deeper than half the woods thickness.
For the cut I use a rather old dovetail saw because I have one and I find it comfortable to use and it produces the correct width cut though a standard hacksaw will work just as well, do not use a standard tenon saw because width of the cut I find is far too wide. The one piece of advice on measurement I can give you is the first bend is always started a little way past the barrel breach block end.
Now place the wood over the edge of a table with the saw cut uppermost and push down on the free end, it will make some cracking noises but only aim to form half of the desired bend only this is to let the wood fibres get comfortable in their new position after about a quarter of an hour push down again to your chosen angle. If you take your time and dont over work the bend you will be surprised how stable this bend will be after you finish, though it is on the fragile side until we make the bend in the wood permanent.
My preferred method is to fill the saw cut with an Epoxy Resin Adhesive with an inert filler I use slate dust only because I have some, failing making your own adhesive filler motor vehicle body filler works well. When the filler is set, I use an abrasive paper on a flat block to smooth it to shape. After the divider is covered with Baize the bends give that look of a smooth transition of direction.
I did the first shaping around the fore end using the divider for the shorter barrel because it was easier to move around in the case, when I was happy with the shape, I transferred the first foot or so of the breach end shape to a piece of card as a template so it could be re set if things were accidently moved. Also this template shape is the same for both barrel dividers because they are Identical at the breach, just their length is different.
