.22 JSB Monster 25grain Pellets.

Was comparing the skirt size of the new batch of 18.1gr and the 25.4g and found the monsters to be at least 0.05mm wider. Quick search on forum and came across resizing by @ajshoots of these so decided to a crude resizing of the skirts from avg 5.7mm down to 5.57mm and 5.53mm (pushing pellet through the pelletgage twice and then y-roll test on glass). Head size is consistent for the batch I have, between 5.52mm and 5.53mm (dropping through 5.53mm hole on pelletgage).

12x resized to 5.57mm and 12x resized to 5.53mm 
Weight 25.4g for all
Distance 30m
Average 830fps/52.7J/38.9fpe (JSB states that these are for 50J+ rifles)
FX Impact 18" ST barrel, Power 5, 145bar regulator, Valve between 2nd & 3rd line

5.57mm skirt pellet group was as before, not good.
10 shots 1inch+ group with 2 flyers way off (not part of 1" group).
All between 828fps and 838fps, except one at 793fps
These pellets were not making a clean round hole either, as earlier tests, thus confirming an unstable/wobbly flight.

5.53mm skirt pellets group was a real surprise (had given up on the ST barrel for these).
10 shots group of 0.6inch!

All between 827fps and 838fps.
Shots 2,3,4 & 5 were literally one hole stacks before hole opened up ...
This may have been a smaller group had the rifle been on the shooting bag instead of the bipod and I was taking rushed shots as well.
Clean round holes which must mean a stable flight.
Also, these pellets at 830fps were hitting just about 0.3inch below the zero of 18.1gr at 880fps (Power C).

Then shot 6 from the tin, no resizing. 780fps, 824fps, 774fps, 835fps, 777fps, 757fps ... and a shotgun/spray pattern as usual.

Going to slug the barrel, measure and then order NOE size dies. This pellet does seem to have potential out of this barrel/rifle, it seems, only if it is resized.

And thanks @ajshoots (Aaron, yes?) for your input on resizing in various threads. 
 
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