Slugging Went Way Too Easy

[Doc_Stihl]

I slugged my new contender barrels yesterdsay. 357 Mag and 44 Mag. Started the 44 with a .451 Lead round ball. Malleted the ball flat and things went easily. As soon as the ball passed the crown it more or less slipped through the rest of the barrel. I pushed it through easily with a dowel. Same result with the 357. 44 slugged .429 and the 357 measured .356.


I'm assuming I have a bur at the crown?

Any way to identify the problem?

I will be slugging from the chamber to half way down and backing it back out as soon as I get time to see what's really going on.