Tuning Wildfire moderator?

[Malsonb]

I bought a wildfire in 2019 and so far I like this airgun. No leaks so far. Trigger is getting better the more I shoot. I installed a altaros reg and the accuracy is better. I put 12 shots under dime at 15 yards. For what the gun is im happy with that. My next mod will be a moderator. Does anyone know the OD of the wildfire barrel?

Thanks,

Brian