Hey Buckshot,
Bullets certainly can be pulled from cartridges, and they can also be loaded backwards, but doing so is not as simple as it may seem. Just pulling a bullet from a surplus 30-06 round and sticking it back in the neck backwards could result in some very destructive results. You might be able to fire such a round with no destructive results, but you just do not know until you try it. A couple of other folks have mentioned you might load a bullet backwards but you should reduce the load, and that is very sound advice.
My dad used to get me to load regular spitzer bullets backwards for him to use in his 30-06 for turkey hunting. I worked up a "backwards" load for him that was safe to shoot, but they were terrible for accuracy. I tried to get him to use a very hard cast bullet or a full metal jacket bullet instead, but somebody had told him about the great idea of shooting regular spitzer hunting bullets backwards, and he would not listen to anything I might suggest. The only thing that finally deterred him from using bullet backwards was when he tried shooting them at the range and could not hit an 8X11 piece of paper at 25 yards.
If you really want to try backwards bullets, I would suggest you put the project on a back burner until you have a good deal of experience reloading and understanding the mechanics of what makes modern cartridges work in a firearm. In my previous paragraph, I mentioned that I "worked up" a load for my dad. The term "worked up" probably does not mean anything to you at this point, but it really is very important in the craft of reloading ammunition. What it means is that I started with a bullet of a specific weight and used what the reloading manuals would consider a minimal powder charge to see if the load would be safe. As you "work up" a load, you would increase the powder in subsequent charges and test them to insure their safety as well as accuracy. At some point while working up a load, you will start getting signs of higher pressure, and you need to know enough to stop. More often than not, best accuracy loads are not at the top end of powder charges for a particular bullet, and those are the things one determines while "working up" a load.
I have always like to experiment with things including reloading activities. However, one should always recognize his limitations and not do things that one does not have the knowledge, skill, and ability to do. I know I have my limitations, and I try to recognize and stay within them. From what you have stated, it seems to me that you need to learn about reloading and leave testing backwards bullets for a future time when you are better equipped to do it safely. When you do get to the point where you are ready to try reloading bullets backward, however, remember that several of us did tell you that accuracy is not one of the best things to expect in them.
Here's hoping you have as much enjoyment at the reloading bench as I have had over the many years I have been doing this.
Best wishes,
Dave Wile