The first time I read about the Winchester model 36 I got the fever. What's not to love about a miniature shotgun?
After a little more research I discovered that garden guns were a British thing. Seems they were pretty popular on the other side of the pond.
Looking on Gun Broker I found various models that could be had for $150 to $800. The only thing stopping me from purchasing one, the ammo. These little guns shoot 9mm rimfire shotshells. It can still be had but the cost is steep. A box of 50 Fiocchi shells on Midway are $26 when they have them. Add on $10 for shipping and you're at almost $0.75 a shot. I could live with that if I could reload them but rimfire is not ideal. So the next question is what do I have that I can build one with? I have an old single shot 20 ga. If I only had some kind of adapter maybe I could make my own version of a miniature shotgun.
So I bought a 20ga to 410/45 Colt adapter from ShortLane. The .410 worked but was not really a "garden gun".
I tried making 45 Colt shot shells but the 20 ga. barrel seemed a little much from them. Not content I had to find a better solution. Then it hit me. I could blow out some 30/30 brass and that would be the ticket. I did a little measuring and came up with a reloadable shell for just a few cents each.
I ordered a piece of drawn over mandrel .75" OD .188" wall tube for the chamber adapter and a 24" piece of drawn over mandrel .5' OD x .035 wall for the barrel.
I was able to pull the specs. for the 20 ga cartridge and the 30/30 chamber from the SAAMI sight and in a couple of hours it was done. The chamber was bored straight walled with a 27/64 " and the head space set using a small boring bar in the lathe. I counter bored the 3" long adapter .5005" ID to a depth of .375" to except the barrel. Press fitted it by holding the barrel in one hand and driving the adapter in with a plastic dead blow hammer.The tape in the photo was used to center the barrel in the bore until a proper bushing can be made.
I decided to cut a 30/30 case at the beginning of the bottleneck for my first test load.
I found I was able to get a 6 grain powder and 115 grain #9 shot load. Almost a perfect replication of the Fiocchi load.
I was able to hit a soda can filled with water at 20 yards with complete penetration.