Just because I want...

Thinking of finding a H&R single shot rifle in some caliber and having the barrel bored out to 30-40 Krag. No 'need', just something I was thinking of doing.

Figure it would definitely be something different. Just didn't know if it was something that was doable or not.

If you want a serious shooter, contact David White of D&T Custom Gunworks. He specialized in H&R and Contender one-offs. He built my 300 Whisper and I couldn't be more happy with it.

why have a barrel bored rather than made?

I second David White, he is the go to guy on H&R rifles. He has done multiple trigger jobs for my H&R's and is always great to do business with.