I thought I would chime in with a few ideas on how to get a barrel made in something other than what you can get from H&R / NEF. Some of these have been mentioned many times and some I don't know of any mention of.
Each of these methods have advantages and disadvantages, I guess it depends on if you want the barrel to be the same profile as a factoy barrel or if you want something longer , shorter , heavy , light ect, plus what it will cost to do it.
I am going to list 6 ways that I know of and I am sure there are others also.
1. You can take a barrel of your choice as long as the first 3.5" of the breech end is a minimum of 1.110 and have a donor underlug welded on such as quickdtoo is waiting on.
2. You can take a rifle or shotgun barrel that fits your frame and cut it at a point where you can get a stub of the length that you need and bore it , thread it and turn and thread your barrel to fit, such as trotterlg has posted very nice pictures and details of how to.
3. You can start with a stub as in the above method and instead of the threading method you bore the stub to the diameter you choose then turn your barrel ( breech end ) to a diameter a few thousands less and solder them together with a hi strength solder or silver braze. ( I have done two this way and have no problems ).
4. You can start with a stub and bore it with a rim recess and turn your barrel to a diameter that will insert through the breech end of the stub and have a larger diameter rim to fit the recess cut in the stub and use a barrel nut or other means to fasten the barrel/stub together , again trotterlg did this a couple of times and it works great.
5. This method you can take a good fitting shotgun barrel either 12, 16, or 20 ga. and just like a barrel liner turn the OD of your rifle barrel to a close fit to the shotgun barrels bore and chamber and rim recess and you can solder or epoxy the rifle barrel inside the shotgun barrel then cut to whatever length you like and you have a barrel that looks like a bull barrel or you can turn the OD of the shotgun barrel to a contour you like, you decide what gauge barrel to work with as this determines how thick or thin your liner barrel will be. ( I have two done this way and again they work great no problems.)
6. This is just a idea that might save you some money or make things easy, You can take a factory handi barrel of the bore size you want and cut the barrel off at a point where you can use the stub and then reuse the same barrel by turning it to fit as in method #4 this way you only need one barrel but remember you will lose about 3.5" from what the barrel length started with so a 26" would finish about 22" and so on for shorter lengths.
Like I stated before there are probably other ways as well but I have done 4 handi barrels in wildcats by using several of these methods and think the handi rifle is just such a platform that make dreams possible. Jedman
