You also use demka rubbers?
My long (30cm) omer power 18mm don't give enough velocity to the spear on my 110 cm gun. The one short size available here is 26cm which will be too short for 110. May be i should change them with demka 19mm rubbers next time
On the other hand 21cm omer 18mm throw 6.25mm shaft quite good on my 80 cm gun
