Everytime.

[Sausagedog 7,381]

I use to be against the wee round but am now very happy with it but my preference  is the tougher constructed 20g. I do not recommend the 17g for anything bigger than hare. Yes they will do it but sooner or later you will get a shallow wound.

I've had no split necks with current production ammo.

[ianm 2,594]

48 minutes ago, Sausagedog said:

I use to be against the wee round but am now very happy with it but my preference  is the tougher constructed 20g. I do not recommend the 17g for anything bigger than hare. Yes they will do it but sooner or later you will get a shallow wound.

I've had no split necks with current production ammo.

What ammo are you using?

[Sausagedog 7,381]

20 minutes ago, ianm said:

What ammo are you using?

I settled on hornady 20gn after  testing Winchester 20 and 17gn.

Remington 17gn and hornady 17gn. 

The Winchester 20gn I really liked but I got a few misfires so they were out!

[Alsone 789]

I suspect it's down to the weather and condensation. You have very moist air and a hot barrel which warms the air inside. Warm air holds more moisture so probably collects some additional moisture. I'm guessing as the barrel cools you reach the dew point and the moisture drops out as condensation. Probably likely with any barrel but as you say, less likely with those that get coated with wax or copper fowling. Good reason to have some form of dessicant or oil patch in the cabinet as well.