I am sure if you do a search you will find several nice tutorials on rolling the fatties with plastic baggies. You did slit the side of the baggie?? We have used venison and hamburger before. Came out great.
The way I do it you can use any ground meat or combination of meats.
Take a gallon ziplock bag and put 1.25 of meat in it. I like to take a pair of scissors and cut a tiny... I repeat... tiny little hole in each corner to let the air out. I then spread it out with my hands through the bag to get it somewhat spread and then I take a rolling pin and roll it out nice and even. You can even it out easily with the rollin pin and get it nice and smooth. I usually put it back in the fridge to cool down at this point laying it flat on a rack. When I take it out I take the scissors and cut the edges from the opening to the botton of the bag. Sometimes I get into a little of the meat but it really doesn't matter, just make sure you don't leave any plastic ziplock in the meat. Once you have it opened up you can stuff it and then roll it up using the bag so that you don't have to handle the meat.... it keeps it uniform. You still have it laying on the ziplock when you drop it onto the bacon. I might pinch the ends so nothing falls out but thats about all the handling I do. Once it is on the bacon which by the way... is laying on saran wrap... I roll it up in the saran wrap... grab the edges and roll it into a chub. Hope this explains it enough for you to try it. I saw a video on it that I've not been able to find since and it really helped me understand how to do it. My first one turned out great. Makes it really easy using this method.
Ok, I searched Youtube and there is avideo showing the rolling. The ziploc method is much easier in terms of flattening your meat and using teh slit bag to roll, but in this video you can see the "missing" piece that is hard to get in text, the actual roll and shaping by your hands.
Ok. Quick update/feedback. The 2nd video I listed is an example of a fattie that is stuffed too much, but greatly shows how to roll & shape. Use the ziploc, much easier. Great video though, a moing picture is worth a 1000 words. I have found good success by making sure my formed meat was selaed well before placing in the bacon weave.
Someone should add these to the how to roll a fattie sticky.