Tuning :)

Hi Chuck,

Interesting and logical info here. I have tried all of the things you mention and have done barrel indexing as well.

I've been having an unusually hard time with my .25 Impact MK2 w PP and 700 mm barrel. Accuracy is just all over the place with slugs. 33.5 gr and 38.5

I've tried extra o-rings, no o-rings, and groups of o-rings. I've tried tuning to several different max speeds with different reg pressures and have gotten the Huma Dual TP and the FX pin probe. Accuracy in general is good one day, terrible the next. and there's always "that flier."

I have an .25 Impact 1 with 600 mm pellet liner and it shoots like a laser W JSB MKI's and very consistent from day to day. Just the other day I put three pellets through on hole measuring 0.134" at 50 yards. Overall average of 7 targets shot hat day was around 0.237" at 50y.

At 75 yards its around 0.5"

But I put that only for comparison and to say that the MK2 is a tough bird to tune. perhaps I'm doing something wrong but I tuned the MK1 in the same manner.

I was wondering if I might IM you and ask a few questions? Otherwise I think that this gun needs to go in to FX. I've had it one year and it's never shot well.

Thanks and appreciate your knowledge with air gunning.

KP
 
Sorry Chuck, I saw this post days earlier but today I just miss it from my mind when I posted a Q in another thread.

My situation is that I have a vertical offset (we don't want to speculate how we got there, I can measure things there if I would want to waste my time).

I need to push in a 0.020" filler gauge between a Pellet Probe Guide (B12) and the Guiding Plate (B14) to have the (Huma) Pellet Probe centerline to the (Huma) transfer port otherwise the Probe is hitting the upper edge 12 a clock on the brass piece.

I was tinkering eventually to bend the rod - Reloading Bar (B19) but that would effect adjustments if I decide to change the Probe in the future.

The second option would be to shim 0.020" in between the Pellet Probe Holder (B10) and the Guide (B12) but no bueno again, I don't want to separate that tiny dowel that is connecting it to the Guide (B12).

The third option would be to cut a slice of steel shim and make it like a skii in between the Guide (B12) and Guiding Plate (B14).

Eventually I can still swap out the ST blocks back to OEM and swallow the expense.

And a very last observation....why the (original FX) cocking handle hitting metal on metal? I placed/stick there a slice of silicon gel pad, but even with a very careful use almost nothing left.
 
My Impact is basically new never been to the field before, Toronto suburb here the clubs are locked down for a year already. So, no wear on it and the rubber ball is in place, and yes, this is my Lego toy and I am very picky with it, zero tolerance 😀.

With this very small usage I can still see a slight little wear in betwean the pin and the probe it doesn't slide in freely on its own but need an effort...and I will fix that asap.For now a moly grease but I will fabricate some sort of low friction sled.

If the Ernest shorter cocking lever cleares the front block hinge maybe that is the way to fix vs redoing a new front block...I won't be able to match the color.