I didn't want to "step on" Roaring Bull's thread on his bag, but he mentioned the strap wasn't adjustable because he had no buckles. There is a way to make an adjustable strap without buckles and that is definitely correct to even the start of the 18th century, though I don't know of any originals that have it.
This type of adjustment was seen in varying forms on most of the European Musket slings and some over the shoulder sword baldrics that go back even further than the 18th century. I made a bunch of War of 1812 sword shoulder baldrics and that's where I got the idea over 20 years ago. It is an adaptation of something that was in common use in the military and something that someone in the 18th century mililia would have seen. That doesn't mean it was popular or used often, but since it is "period" in form, I don't see why someone else in that time period could not have made such a thing. Necessity was even MORE the Mother of Invention then.
Here is a link to a musket sling I will use to describe how to make the adjustable straps.
http://www.najecki.com/repro/musket/SlingE.htmlThe short bottom strap at the back of the bag would have a sewn on loop at the top - like the loop you see in the top picture and at the bottom of the top picture on the left side. You would also make a sliding loop that goes on the short strap between the bag and sewn on top loop. You can see a sliding loop in the same top photograph and on the bottom right side. The sliding loop will go over both pieces of the rear strap and keep the two pieces together.
The rear end of the long front strap could be cut square; but it would look better as a half circle, spear point, or even with clipped ends on it. Whatever suits your fancy. Now, to make it adjustable, you have to punch four holes near the end. If you look at the bottom picture in the link, you see four punched holes near the end of the strap that a leather "wang" is threaded through and tied. AFTER you punch those holes, you slide the long strap end through the sewn on loop at the top of the shorter/rear strap and through the sliding loop. Then you use those four holes as a guide to punch a series of four holes in the short rear strap to match. You would make the first set of holes in the lower strap close to the top of the bag. Then make two or three more sets of holes going up the short strap. That allows you to move the long strap up the short strap and lengthen the overall length of the entire adjustable strap when you wear a heavy coat for example. After you move the strap to the position you want, then you tie the leather "wang" or strip as shown in the bottom picture of the link. The sliding leather loop is positioned between where you tie the two straps together and the sewn on loop.
If you REALLY wanted to get fancy, you could punch two series of four holes in the end of the long strap and use two leather "wangs" or strips to tie the two straps together. I'm not sure I would advise that because a whole bunch of holes would weaken the straps. Two or even three sets of holes would not weaken the lower strap that much.
If anyone is wondering about the strength of tying two pieces of leather together this way, then I would offer the evidence that this is the way musket slings were closed near the butt and there is a LOT more stress on a musket sling than on a shooting pouch.
Gus
