I have a few vintage Red Head LOM cases for barrel lengths 28 to 32".
For sporting clays and use in the field especially to protect the gun in a duck boat, I use a leather slip I bought from England.
This guy is on Ebay and I was able to get one less than listed on his website. Thick leather and thick wool interior for protection. I have been able to fit my 34" five frame hammer gun although it is a little tight.
Very well made.
https://johnshooter.com/subcategory/...ng/Gun%20Slips