best ammo for fx slug liner 25 cal

The liners were designed around a certain size/diameter.

For instance, .217 for 22 caliber. Mine shoot NSA and Varmint Knocker slugs just fine.....both .217

The .218 sized slugs shoot well too. Some barrels will shoot one size better than the other.

Slugs are also more sensitive to the proper twist rate and velocity for their weight compared to pellets, which don't seem to be as affected by those variables.
 
Alright, I dont think h&n grizzly 25 cal have match with fx slug liner, I push one slug through and it went with ease and I tried looking through the barrel while one is inside, this is what I see:



1550743598_7968761095c6e782e3203d3.97248104_DSC_0362.JPG


But when I push the slug to very end (last 3 cm) of the barrel it gets tight fit! This barrel clearly has choke at the end, I thought slug barrel should not have any choke? First question will be: Am I handling slug liner? Yes this is slug liner, clearly higher twist rate
1550744958_5285645465c6e7d7e3fda37.28816453_15507447980771059376984289943246.jpg


Here is the slug at end of the barrel, looking from exit side, no more light passing from the sides of slug:

1550745201_115732035c6e7e71427493.70483420_15507450116444206275737009062252.jpg