As best as I can determine, the Hadley's Patent Device (H.P.D.) for using Rim-Fire cartridges in the Maynard Model 1873 breech piece, was offered as a factory installed option to customers who, either at the time of purchase of the rifle, or after the initial purchase if the customer/owner, were to return the breech piece to Mass. Arms Company.  Said another way, I do not believe that the H.P.D. was ever offered to the gunsmithing trade in order to accomplish a non-O.E.M. installation.  Non do I believe that an owner was able to purchase a H.P.D. directly from the factory for a so called "home" or "garage" project.

There are several reasons to support my conclusions, which I won't take the time now to explain.  My approach for achieving the same result as the use of the H.P.D., would be to use the Maynard breech piece as it was intended to be used, with the addition of a "rim fire" barrel.

The rim fire (R.F.) barrel would be identical to the central fire barrel, save and except for the center line axis of the R.F., which would be offset with a correspondingly off-set chamber.  Accordingly, the C.F. firing pin would strike the offset cartridge case on its rim and ignite the priming compound.

This is nothing new conceptually, but the particular application to the Maynard might be.  The off-set barrel axis is sometime used with .22 R.F. barrel inserts which allow a C.F. rifle to shoot a .22 R.F. cartridge.  Not match quality result regarding accuracy I don't believe.

By adopting my methodology, both the 1873 AND the 1882 breech pieces could be used to shoot R.F. ammunition simple by the installation with the special R.F. barrel I've described above.

C.M.M.

Page 19 of the Layman book show a comparison of the center fire barrel breach and an offset rimfire breach, if you are interested.

I have been wanting to make a rimfire barrel for a while; still trying to figure out all the setups. Guess I'll need to pick John's brain on this one. 

Will

Webb, I have two maynards with .22 rf barrels, and they both much fun to shoot. One was made by Mr Bly, and the other one made by Mr Pope. Will you be at Gretna this month? I regularly shoot the Pope Rf barrel in Charlie's match there. You are welcome to try them out. Later, moodyholler

Mr Bly's work is superb. I also shoot a 32-35, 35-30, 20 g, 25-25 stevens, 40-40, and 64 cal shot. What else other than a contender can you have such a variety of calibers for? I have had a Maynard since 2001, before they were cool. My long-time single shot Mentor says HW's, and Borchardts are the only way to go and gives me Hades about my Maynards, but deep down, I think he is jealous!!! HJepburns, H/W's and Borchardts come and go, but I still have my multi- barrel sets! Later, moodyholler