Nat Sherman #536 in a Boswell Rhodesian...paired with Samuel Smith Organic Chocolate Stout.

Hi Everyone, as mentioned in my introduction post, BOTL needs quite a bit of updating, patching and whatever else I might come across. Over the next few weekends BOTL may be unreachable on occasion as I do migrations or updates, etc. Just be patient - we'll be back! I'll generally try to keep these maintenances until later in the evenings.
Is the stopper made of rubber? Can it be trimmed to allow half a bowl or better?Still don't get it... I can only pack like a quarter bowl other wise the cap comes off... What am I doing wrong?
It's more of a soft foam so yes but I shelved it anyway! Thanks though that's a good idea.Is the stopper made of rubber? Can it be trimmed to allow half a bowl or better?