There was a few gunsmiths doing relining business. You may want to try this one:
http://www.redmansrifling.com/relining.htm
People had positive feedback on him. Sounds like he uses a special kind of glue to fix the liner inside. The charge is reasonable too. Back a week ago, there was a seller listing a reblued conehammer, I thought if it's around $1k, I would buy it to give redman a try to see how good his craftmanship is, why not, the bore is already a smooth bore and the gun was reblued. But the gun did not come. Not sure he does .30 Luger liner or not, but should be easy for him.