You got the specs from the other posts ahead of me. Rice, 54 caliber, radius groove rifled at one turn in 66 inches. That barrel is a honey! It will yield a real fine rifle. Once I handled a rifle with a swamped barrel I never wanted to go back to a gun with a straight octagon barrel again!
If you are letting the barrel in by hand a swamped barrel is no more difficult to let in than a straight octagon barrel. Figure about 3 to 4 hours per foot of barrel for a hand inletting job. If you want some guidance on how to do it let me know, I have an MSWord file that is a set of instructions on hand in-letting a barrel that you might find helpful. I can email it off to you.
A word of caution - on every barrel I have ever used, regardless of vendor, I have found it advisable to pull the breech plug and polish the breech-plug face. Sometimes this changes the seating depth of the breechplug! Do this FIRST, before letting in your barrel and putting on your lugs.
Best Regards,
John Cholin