Gunner, expect to always get a handful of wrinkled balls until the mold heats up. However, if this problem continues throughout your session, your lead is probably not hot enough. A quick and simple test I use is to check the puddle over the sprue after the pour is completed. If the puddle stays "wet" for at least two or three seconds, your lead is suffiently hot. If it hardens as soon as you stop pouring, you're probably going to get wrinkles.
If you are using the propane powered coleman stove, there are a few tricks you can do to keep the temp up.
First, just keep enough lead melted in your pan, or pot, so that you can get a full pour amount in your ladle(or whatever you use for a ladle). When you find you can't scoop up enough to complete a pour, add just enough lead so that you again get a sufficient ladle-full. I usually try to keep my pan at about 1/2" full. Less lead in the pan gets hotter.
Second, turn the setting all the way up and pay attention to the sound of your flame. I usually find that after about 45 minutes of burning on "high", the sounds starts to slowly diminish, which means the flame is cooling and the lead is also cooling. If this is happening to you, I suggest you change the bottle out with a new one, (carefully of course, everything is HOT) and save the half empty bottle for camping. I don't think any lead hazzard exists with re-using the bottle for cooking.
Also, find a protected place to melt your lead, mostly out of the wind. It's a good safety practice to have a slight breeze going when you pour, but any wind stronger than that can keep your lead from heating up to it's full potential. Hope this helps, good luck. Bill