I was using JSB match 4.49's in my Steyr's because that was what they were tested with. I'd been suffering with unexplained shots but thought it was me and it was my LP50e magazine that allerted me to a problem, most were loose enough to cause the problem described of pellets falling out but some were tight.
When I inspected them with my ordinary glasses and a magnifying glass, and scales, I discovered that the tins contained mixed sizes and weights! I had bought a sleeve (10 tins) and was well through it, I had noticed the tightness phenomena before but had not checked, mainly because I can't see close up with my shooting glasses and had just put it down to a lead build up in the magazine (Doh!!).
Cursing JSB's quality control I carefully checked all the pellets in a tin and separated them into 4.49 light and 4.50 heavy and bench tested them. Both produced very tight groups but the point of impact was significantly different.
Lesson, JSB quality control is very suspect, and differing pellets shot as a group may cause problems, I now use R10.
Best regards
Robin
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?