Dear AR15ers, I would like to improve my shooting technique with my standards SF98 (just a SF92 but cal. 9x21mm)
This is so far my best group of 25 rnds at 10 meters, the white circle is 20cm diameter.
You're getting vertical stringing. This is being caused by the too weak recoil spring heating up, and the pistol unlocking sooner the hotter the spring gets (less spring tension due to heat). Get your hands on a 15, threw 20 lb recoil springs and start seeing what spring it takes in the pistol to get the spent case to eject about 5 feet. This correct tension spring will cut down on the vertical oblong stringing for everything but the last round flyer*.
Basics are whatever the group is wide; it should be tall as well.
* Last round flyer is caused by the mag being empty, and not having a mag loaded round pushing the barrel repeatable back up as before. To solve this problem, you need to add a set for the barrel bottom tension.
Practice, paisano, practice!