Part 4- Molding
This is where the holster really comes together. Up to now, I've shown how to lay out the leather and cut the shapes; this is where we actually get to work it.
Next, get a pan of warm water. Make sure the pan is large enough to fit the largest piece of leather, laid flat, and deep enough to fit the finished holster.
We will lay the holster up from the inside, working our way out. Take the innermost layer of leather, and soak it in the warm water for several minutes- most of the time, it will make bubbles; this is normal, just the water displacing any voids in the leather. Once it is saturated, the leather will become soft and pliable. As it dries, it will maintain its shape.
But first, we have to give it that shape. Remove your piece of leather from the water and fold it around your gun. Don't worry too much about having it perfectly positioned, that's why we cut every piece a little extra large. We won't trim anything until its molded and dry. Using your fingers at first, and then a molding horn (in a pinch, any hard, smooth object of the right shape will work) begin to mold and push the leather into the gun. The leather will stretch as it molds, so start at the fold and work towards the stitching. Areas to pay special attention to- the trigger guard, the ejection port, and the controls.
When working the ejection port, the object is simple. The majority of the time, the ejection port is large, precise indentation on the side of the gun. This makes it a perfect spot to get some retention, as it makes for a great detent. What you want to do is work the leather down to fill the hole in the slide. Once the leather dries, this will help the gun to 'snap' into the holster.
The trigger guard. This is where most of the retentionand the fit of the holster is accomplished. Use the small end of a molding horn here, or some other instrument, to mold the leather tight and flat in front of the trigger guard. By molding closely around the bow of the trigger guard, and pushing in all the way to flat, you will create a wall- a flat point, where the gun will stop firmly from pushing any farther. If you don't get this area pushed all the way tight, you will end with a 'pouch' effect, where it would be possible to push the gun deeper in, leaving movement to the retention, which will make the holster less positive and eventually could stress the stitches. To that end, you will also want to mold somewhat inside the trigger guard- but carefully. We want to get enough of a mold to snap the gun into place and hold firmly, but not so much as to impact the trigger. This is especially important on single actions with very light triggers, but a principle is a principle, and I don't like anything touching the trigger besides my trigger finger.
The controls. The molding we do around the controls is not for retention, but for shape and to account for them in the thickness of the gun. Some controls, such as slide stops and takedown levers, will protrude from the side of the gun only a little. In these areas, work the leather around them a little bit, to make certain that the leather is laying flat to the side of the gun. Once the holster is assembled, the leather will not push away on account of the slide stop. Other controls are a little trickier, and will require some planning. First example, the magazine release. On many firearms, this is a button, so we will want to make sure nothing pushes that button, dumping the magazine out on the ground (or worse, dropping it loose enough to cause it fall out or otherwise cause a stoppage when needed the most). There are two ways to go about this, that I've found. The first way is to make sure BOTH sides of the button are equally covered. Once molded tight, I've found that this tends to keep the mag release stable and centered- its difficult to get enough flex in that much leather to drop the magazine accidentally. The other way is to make sure that the button is not touched at all, either by lowering the rim of the holster, or carving a notch for it. Note: In this holster, I did the first. If it has ever caused the magazine to be released, I've not been made aware of it. Next example, the safety. We don't want our holster changing the safety setting after holstering- make sure there is a molded detent for your safety in both the Safe and Fire positions.
It is important to note here that these steps are not a one-time thing. You will find, as you build your holster, that the more pieces you put together, the more times you will have to soak and mold your holster. Just be careful to place the gun in the exact same spot, and you will be fine. Also, after the first few pieces start to take their molding, you can begin to trim the holster towards it's final shape.
Here are links to the other steps in this process