Rob..I gave up on the batch and bought a fresh one, thru my TX it is exactly how I stated, from well under 700fps to hitting 11.5 at 780...i have nothing to gain from telling porkies here, it is the reason I spent money on the pelletgage so i could at least see what was going on with the pellets. I spend many hours reworking springers, I was testing with a batch of exacts that on the whole were showing 9fpe...I moved to superfields and was hitting 13fpe at one stage...its was a good job im not totally blinked to exacts.
Something else I found, power plant set up is critical, going from a 25mm piston to a 22mm piston opened the can of worms wider than I liked with regards to JSB die, lucky for me I just happen to have tins of most everything so I just started with prems and worked thru superdomes, superfields, LRG's, FTT's etc and found what would at least give good solid FPS performance and then moved to accuracy.
Maybe those early 2015 tins were just made on a friday late afternoon....its hard to say, they shoot thru the LGU just fine, they do NOT shoot thru my TX fine and remember my TX is seriously refined now, how many people do you know with a TX that runs a 22mmpiston with 83mm stroke?
So lets forget the rouge batch, the graph shows clearly 2013 pellets outperforming 2015 pellets that were sorted for size with regard to power output, I have not tested accuracy with them yet in the TX but I have shot the 4.51's in the LGU and they were seriously good.
So my conclusion is this, the barrel on the TX right now does not like the newer batches of JSB, this may be more pronounced since I refined the power plant. I can tell you the pellet fit with the 2013's is tighter than the measured 2015's...there is more resistance from the pellets going into the end of the barrel.
Hence...I want to try another barrel on the TX, the issue could just be the lead in was fine with the older pellets, or running 41CC of compressed air bellied out the pellets for a better seal than running 29CC of air does now.
Its probably something that simple.
Edit..I feel I need to clarify here, the 2015exacts are poor thru the TX as per the graph, however the tighter barrel on the LGU suits them just fine, velocity in the TX is 720, velocity on the LGU 760 to 770, 2013 velocity on the TX 755 to 765, in the LGU 770.
It can only be the barrel...the pellets have changed BUT they work fine in tighter barrels.
Last edited by bigtoe; 19th July 2015 at 10:52 PM.