Ich zitiere von der Seite vom Eric Uptagrafft:
Q: Should I get my son or daughter a tuner?
A: A tuner is only going to be useful to shooters that are already pretty good. There is a good chance that if they don't already shoot 594 prone on the metric 50m target they won't be able to tell the difference. The added complexity of another variable can do more harm than good.
Q: In that case, should I get them a regular extension tube?
A: Bloop tubes are handy for us more "experienced" shooters. The added sight radius can make it easier for older eyes to see the front sight clearly. Young shooters don't necessarily need a bloop tube, especially if they want one just because "everyone else has one". Sergei Martynov doesn't use one and he is arguably the world's best prone shooter over the last decade. The added weight of a bloop tube for smaller shooters can cause excessive arm/wrist pain in the sling positions. However, if you have a short barrel (500mm Anschutz) one is required.