Greetings My Dear Monsieur Burrows
Firstly you will probably want this in the STORM area rather than the Leather shop
but no worries, we will work it out
Second, is this a C&B or Cartridge open top?
Third, is it Uberti?
This exact problem is common in Uberti's and is the result of a "too short" arbor.
the simplest fix is to clean out the arbor hole extremely well and a #10 spilkt washer dropped down the hole.
once this is in the STORM forum Coffin or Goon or Larsen or whatsisname will probably be all over this on your behalf.
Can you tell we are a helpfull bunch?
yhs
prof marvel