thanks guys for the feed back, got some things to mill about (pun intended

)
i do realise it will consume a great deal of time, so maybe ill just put it on the back burner for now
that whitney-phenix design is actually what i was pondering as less mechanicly complicated then a falling block

though it would require sodering/welding
as is it seems im not ready for this major undertaking
Im just going to be blunt with you here, no offense intended.
99 percent of most of these "build my own gun from barstock" threads dont ever make it to the poster even TRYING to make a single part. Search the net and there are dozens of threads of people who post their musings and never get off their rears and make a part. I see these questions more now and run into lots of people who ask about making some widget or how to shape this metal project when they have no idea how. I can explain till Im blue in the face how they can make their toy, but I can see when they look down and to the side that they don't have the slightest urge to even try out of fear of failing, they just like to talk about it.
Ability, tooling, skills and available finances are immaterial. There is ALWAYS a way to make something. The "no time" excuse is the worst, if people have time to watch 3 hours of tv a night, they have LOTS of free time. People have time to run on a treadmill like a hamster for 2 hours a day trying to burn excess calories for a week of doing nothing. Get a file, vice, a hack saw and a cold chisel and try shaping some metal and you'l throw the gym pass out the window. During my time as a machinist I ran into precious few fat ones, I never worked in a CNC shop mind you.
If you start cutting metal TODAY and maybe bite the bullet and buy some drawings, a book or an old junker action to copy you'l be making a huge step. If you make so much as one solitary screw, you will have accomplished more then most. If you dont finish it, thats fine, put your screw in a coffee can and put it somewhere you can find it again. Sooner or later you will make another screw and another screw and a front sight and it will start to snowball. Focus on tangible things like finished parts, and not on overthinking things. Worried about the strength of a black powder gun? All thats holding a rolling block is that one rear pivot pin.............and they work fine.
For you to get any momentum on your project you need to push yourself to make the first peice, if you screw it up who cares? Try again.
Dont have a lathe? Go build one!!
http://www.vintageprojects.com/machine-shop/hobby-lathe-plans.html
http://www.lindsaybks.com/dgjp/djgbk/series/index.html
Trust me, when I started my first day as a machinist apprentice, I thought I made a huge mistake, I didn't have a clue what I was doing and there are times when thats STILL the case!!. With each more difficult/complex part to make or fix that was flopped in front of me there were times I wondered how I was going to feed myself, put gas in the car, keep my job and not make an arse of myself. But there was one thing for certain, I could never shrug my shoulders and give up, to do that would be to give up on my hopes/dreams, maybe quit/be fired and likely loose everything.
Quiting/giving up on something is a skill that is learned, and takes practice. Its not easy to give up on what you want at first, but it slowly gets easier as you do it more and more. You dont want to be good at quitting at something before you even try.
So you have to try, if you screw up and you probably will once in awhile, you start again. That is how tangible things are built.
There are alot of men I have met, who wish they built things and not necessarily as a living. Many have made lots of money, have nice looking wives, houses and cars but are emotionally unsatisfied because they never fed that creative urge. And many regret it to their dying days. Alot spend their time reading books on the subject or web posts or look at pictures, but they never try and never get to feel the sense of the purest satisfaction that men can feel when they eventually succeed at transforming whatever block of wood, steel, stone or clay that they have bled, cried and sworn over into what they wanted. Some find solace in whiskey, women, family, success, money, credit, medication or denial. But the urge to make something is a very personal thing that only you can satisfy, your brain is your worst enemy in this case, because the urge will not go away if you truly want this.
Go out of your comfort zone and try. Because thats the only way things are built from nothing. You're only a few thousand file strokes away from a finished rifle action!!!