I do not think any powder company has samplers for sale. For one thing what would they pack? What powders would they put in a sampler? Say four powders with similar burning rates or four with greatly differentiating burning rates? 4 ounces will only get you 70 shots at 25 grains a shot. If you are using say 35 grains it will get you only 50 shots. I need more than 70 shots to figure out if it is going to work for me. I generally load up 10 rounds of every charge weight in .5 grain increments. If there is a 4 grain difference from low to high that is 8 different loads at 10 shots each - 80 rounds. After shooting them up, I then load up 20 in the most likely powder weight. If that looks good, I then load up 20 more in 5 shot lots at different distances from the lands. I then pick the best and load up 20 more (4 - five shot groups) in that length to verify bullet seating depth. As you see I can go through quite a bit of powder before I get my ideal load. I have not even mentioned using different bullet weights, which would add even more testing. I do not think that 4 ounces would be enough to get it figured out. Of course, I have tried powders that I can tell in 20 - 25 shots that it is not going to work for me. I do not have any guns that take slow burning powder, so I do not have any of those on hand. I do have several in the fast and medium burning ranges. I do not have any magnums. I have in the neighborhood of 8 fast burning powders and 8 or so in the medium burning range - depending on where you make the cut off. I generally buy my powder 2 pounds at a time in the medium range and 1 pound in the faster burning powders. That is a little over kill, but once I figure out what I want I do not want to be out of powder either. If does not work out then I generally have enough left over to try in a different gun or a different bullet weight later and if does work out, I buy a 4 pound or 8 pound keg of it. Good Luck and Good Shooting