I've been itching for some time to do this and finally got all my ducks in a row and have succeeded. Bear with me as it's a bit long and I'll try to detail a bit. As an introduction, I've been wanting to make a .22 caliber muzzle loader, but at the same time, I really thought why make a new gun just for this, there's got to be a way to make a .22 work for muzzle loading easily. As a platform for my project, I decided to use my Marlin 70P "Papoose" since it has an easy to access barrel end and breaks down into a nice case:
Big issue is that I still want to be able to use it with std. .22 LR ammo as well. So with a bit of research and testing I came up with the following tap:
Which is the correct tap size to directly tap the chamber of a .22 rimfire and small enough thread to avoid having brass extruding itself into the threads when shooting regular ammo. Here's the nipple:
Sorry, phone doesn't do well with the close-up, so later I'll try to take some better pics.
Anyway, I ran the tap into the chamber of the Papoose barrel about 3/8":
Once this was done, I made sure there were no burrs with a round file and then went out and shot up a clip of ammo... Good to go so far! No apparent effect on the ammunition extraction.
So now I thread in the nipple with a tiny bit of breechplug grease that I use on my Muzzle loaders:
Then I re-attach the barrel to the receiver of the Papoose:
Finally, I use my smallest Lee Dipper (.3cc) to measure out some Goex ffffg:
For ammo, I've picked up two things, first off round lead BB's made by Gamo, but they are too loose and roll out the bore, so I use thermal recept paper to create a wad. Once the balls are started, I rip off the tail and ram it down.
I have picked up some 30gr. NAA CBB style bullets too, but haven't had a chance to test with them yet:
So finally, I load up my brass cap dispenser with Remington #11 caps and step out on the back porch with the breech locked back in it's retaining divet:
Anyway, I am still working on the bolt release mechanism, but basically, It acts as the hammer and fires the cap. I have drilled a small hole in the retaining divet on the left of the frame and I'm making a spring clip, which can be snapped on when wanting to do the muzzle loading:
Rifle shot pretty close to POA, but it's a rainy day here and didn't have much time to set up paper and such. Will post back more when I can put some on paper too.
I was simply letting the bolt go manually today.