The owl kits are made the same as you would make a deer grunt call. There is a tutorial here
http://www.thogamecalls.com/PDF%20Tutorials/TurningDeerGruntCalls.pdfThe only change you need to make is at the stopper end that the guts fit into. Obviously you do not turn it to hold an extension tube, so you can vary the length. The key is that you need to restrict the air flow coming out of the stopper. Back Pressure is what makes these calls work. There are several ways to do it. You can use a 1/2 inch rubber bushing and insert it in the end of the call, or you can turn a piece of wood or metal down to 1/2 inch and glue that in. You will have to drill the wood or even the busing out. The amount you restrict the air flow will depend on how long your barrel is and how long your stopper is. Even restricted, you will still need to apply some back pressure with your hand over the end of the stopper.
When I make owl calls, I have two different dowels drilled 1/4 and 3/8 I use them to tune the call to my liking. Even then, you might still need to open up a bit depending again on the barrel length and the stopper length. I like about a 4 inch long barrel and 2 to 2 1/2 stopper on my owl calls, but that is not set in stone. I have seen some very good ones with 4 1/2 barrels and 3 inch stoppers, and I have made some with 3 1/2 inch barrels and 2 inch stoppers that worked well too. Again, the key is to restrict the air flow coming out of the call.
Let us know if you need more help, or, if you want you can always call the shop at 603-867-1018 and I will try and help as much as I can.
Al @ THO
