Targets are usually the last concern of a shooter that is headed to the field for a day of shooting fun. Heck, almost anything can be a target in the field as long as it is in a safe direction to shoot.. But if you are going to the range for a purpose like zeroing your rifle at a certain distance or testing a new brand or lot of ammo, having the right target can give you more accurate and faster results.
For zeroing or testing new ammo, most of my testing is done at 50 yards with rimfires. For getting these jobs done efficiently there is nothing more important than instant feedback on every shot. The splatterburst variety of targets provide this with a bright yellow burst of color around each bullet impact. Easily seen from 50 yards away and the quick feedback can be a big plus in letting you know if the shot was well executed or not.
Here are the targets I use for these purposes. You might not think they make a big difference but believe they are much better than shooting at a piece of cardboard with a black dot made by an ink pen. You are never guessing which shot made which hole, etc.
Splatterburst has many different target designs but for our purposes. I prefer the one with mulitple bulls eyes. With one target setting I can zero, check, and test several rounds before having to go down and reset the target. All of the bullseyes are 3 inches in diameter. You get 15 bullseyes on one target sheet and the price is only around a dollar per sheet.
Once I'm zeroed and ready to go long and have some fun, I love the metal swinger variety of target . Again you get immediate feedback when you hit in the distinct "plink" sound which can get addicting. I like to have several set out at different ranges from 25 out to 250 yards. Going back and forth between targets will really give you a work out with your scope and rifle. There is no better way to prepare for a NRL22 match or a weekend prairie dog hunt.
The swingers I use are 1/10th scale metalic silhouette targets which means they are 1/10 the size of full size target used at 500 meters for big bore rifles. This is the same scale used in sanctioned smallbore silhouette matches. I use these at distances out to 150 yards or so. For further distances I recommend a 4 to 8 inch round gong like the one pictured below. Of course this depends on how good your are and how much of a challenge you are up to.