Given any object you desire, and any readily and easily obtained propellant, what is the farthest the average person can “shoot” something straight up. Can a bullet given the propper amount of gunpowder be sent outside our atmosphere? Remember, I am asking about readily and easily obtained, and if you work at NASA, no need to be a smarty pants 
well, “Nine tonnes of special supergun propellant”, ill just go down to the local hardware store and pick some of that up
An average person can certainly build model rockets.
mmmkay, and how high has one gone?
No idea. I was going to check Guiness’s website, but it got cursed Flash crap on the frontpage and I absolutely hate Flash when it is used in place of regular navigation aids.
It depends on the resources of the “average person.” How much money can he/she save up for this project? How many nights working in the garage?
I think the best bet is a hydrogen or helium balloon. Here is a photo of a small 100,000 ft weather balloon being launched - looks pretty affordable to me. Hydrogen would be far cheper, of course.
With a launch velocity of 3000 ft/sec, which is high but probably within reach for some hand held rifles, and launched straight up in a vacuum from a non-rotating platform a bullet would reach about 26.5 miles altitude. Air resistance would knock off a little, but the bullet would reach 10000 ft. in 3.3 sec and that is above about half the atmosphere. Maybe reduce the altitude by 3 miles?
That is certainly outside the vast majority of our atmosphere.
The effect of atmospheric friction severely limits the maximum altitude of bullets or shells. This M3 3" anti-aircraft gun from WWII could deliver shells to 27,900 feet. Building something like the M3 would likely stretch the limits of any backyard weapons smith. Even today, the B52 bomber flying at ~55,000 feet is not threatened by rifles or most ground based guns.
The father of modern rocketry, Robert Goddard, built rockets virtually in his back yard. His model L-13 reached an altitude of 1.7 miles. You can buy rocket kits today that can reach that altitude or higher.
30k - 40k feet is certainly achievable with high power model rocketry.
My understanding is the above what is allowed for “high power model rocket” class would fall in a class called “amateur rocketry”. These can be even bigger.
I am probably missing something, but it appears that anything can be flown as long as it has no guidance. Guidance classifies it as a missle.
When I lived in southern CA, I have participated in the launch of a “K” class model rocket that achieved around 13k feet. “G” class is the largest I have done personally. That is as high as you can buy the engines without a license.
“P” class is the largest consumer class engine. It has a maximum impulse of 18409 lbsSec of thrust. 18409lbsSecs could be 18409lbs for one second, or half that for 2, or a third that for 3, etc… 600 lbs for 3 seconds can put something pretty damn high in the air. Anything making more total impulse than this falls in that above mentioned class of “amateur rocketry”.
Dang, just looked an amateur rocketry site. They have links to movies on their front page of a rocket that exceeded 50 miles altitude. www.rocketry.org
At the end of the inflight video you can actually see the curvature of the earth and the sky turning black much above the horizon. Pretty impressive.