How to shorten a barrel?

[browningautorifle]

I sporterized a number of sporter #4's and #1mk3's some years back. All I did was to chuck the barrelled action up in the lathe and cut and crown the barrel where it came through. That gave me about 18 1/2 " of barrel. I turned the crown and turned down the outside diameter until I could tap the front sight on. I cross pinned them again and that was that. They worked for truck guns and the guys were all overjoyed to get them. BUT, I had a lathe to work with...