Question to BR shooters - what pellets are the best BC in .25 for long range?

[bigHUN]

FX Impact .25 MK2 PP, 700 mm Superior Heavy liner (just switched out recently from STX-A).
Liner indexing done and currently entertaining with barrel harmonics tuner, as much the weather allows.
I am weight sorting my pellets, washing and lubing, so the effort and time is priceless, I still need to figure some testing tricks how to prevent the occasional fliers. If this just possible anyhow.
In past several months I was shooting JSB 34gr MK2 and discovered some inconsistencies with pellet skirts, I assume again this can lead to internal friction inconsistencies and this can lead to ..... a whole chain reaction.
For these above reasons I switched out the liner and started buying slugs, currently shooting ZAN 37 grain and next is to test 41 grain. The results I am seeing @ 100 promising. The POI grouping from average 1-3/4" with 34gr pellets (860-890 fps),  shrink to about 1" with 37gr slugs (920-940 fps).
I would like to train and prepare for next year competition season and over the winter prepare a batch of pellets again.
What is the experience with some other Brand pellets in .25 from a view of BC that can be successfully used for long range scoring?

[bigHUN]

OK  since nobody answered to above question I am converting my Impact to a slug gun. I will be back 

[rsterne]

The JSB 34 gr. King Heavy Mk2 pellets have about the best BC you can find in .25 cal for a pellet.... They rival or exceed the BC of the .30 cal JSBs.... Slugs do have a better BC, mostly because they are heavier.... Accuracy, of course, is king.... 

Bob

[Corny]

The mk1 king heavies have slightly increased BC
I use .062 shooting at 895fps

However, I know jsb has been messing with the skirt on those….it changed last fall.

I know with my mk2 impact, it was pretty easy getting 1.5”- 2” groups right out of the tin with those pellets. At 100y

[FastJ]

Jsb heavy Mk2 is best pellet for .25 what im used

[FastJ]

Also have to add experience from impact. When got mine was pretty disapointment.
All over web have videos where people shoot eyes blinded one hole 300yd with all friking gadgets.  Yes partly joke but maybe you get the point. From boxs mags strugle, valve leaks every @$%^. After it any ammo 2 moa avarage.
Tell here some previus guns avarage. Hatsan, 1.5 moa, war 1-1.2, wildcat 0.5-1. Then impact 2moa.. got me now?
Realized its just rough blank what you get 2k. Have to finish and fine tune everything. That dropped my motivation. Did not do anything with it a year. Had to restart and im close what wildcat was.

[bigHUN]

I did some porting and hardware upgrades over this past winter - again, and ended up at the other=opposite side of a red line.
It just happened that modding this-and-that I got to a way high power curve, and without taking my Impact apart I cannot shoot both pellets and slugs only by turning the power wheel...
I was searching for a max numbers the MK2 PP can deliver, not because I need the speed but only to see how far I can reach.
I got some 37 grain, 41-44-46 grain slugs for testing at 100 meters with in mind that eventually I will start shooting ELR=200 meters, but also collected couple tins of 34 grain MK2's and MK1's.
The llightest 37gr slugs slowest I can shoot is 105 Joules @ 120 bars, and I can only go up with power. 41 grain I got 126 Joules @ 150 bars, and I can reach 960 fps with 46 gr ZAN's as well.
Not sure at the moment which slug will be a best wind cutter at my 200 range.
Looks like my Impact will stay now with slugs...this was a learning curve as well. Before my testing I could not imagine why people having dedicated slug guns and dedicated pellet guns...Now I learned.