I'm not sure if this is the right location for this question, but here goes since you guys are the Kral experts :-)
1) Can the hammer spring be accessed without degassing the rifle? Is the brass tubing connecting the rear block and bottle flexible enough to drop the block down to access the hammer spring?
2) If so, how much velocity change does one turn bring? (I assume it will be self evident which direction adds tension here...) I'm looking to drop the average velocity with jsb 18s to about 870 or so.