I would test fire the rifle before fooling around with lapping the barrel. I've seen Green Mountain barrels perform as well as any. What is really important is getting the right bullet. You may want to call GM, if you don't have the numbers, and get groove and bore specs. Steve Brooks can make you any bullet needed.

Hi TimK
What is the model number on the lyman receiver sight that you used.
Did you glass bed the forarm? 
Thanks
Swifty

I have no general comments to offer about the rifle (no personal experience with it, specifically). Steve Durren will be the one to give you actual user info regarding the rifle.

However, I did compete in BPCR Silhouette for over fifteen years. That experience allows me to make an observation or two regarding BPCR's in general.

Make quite sure that the particular rifle is approved for BPCR Silhouette and/or long range. There are specific qualifications that need to be met and these folks have NO sense of humor regarding shooting an unapproved rifle. I have no argument regarding the equipment, it is just that you need to be sure it will be accepted before you spend a lot of money equipping a rifle that will not be allowed to compete. It HAS happened, believe me.

If your rifle has a Green Mountain barrel on it, you will probably find that it's interior should be as good as it needs to be. I wouldn't do a thing to the inside - it's already "Ready". Steve's rifle shoots well (the project rifle) so I expect that your's will (bedding the forend is probably a REALLY good idea).

Sights - if you intend to shoot "Mid to Long range" you will need a vernier tang sight. A Lyman or other brand similar sight will NOT have the range needed to get hits from 200-1000 yards like a true long range vernier sight will do. I can recommend the "Parts Unknown" ( the Ukrainian sights)verniers as well as the Browning on the "low end" as well as the Baldwin and MVA sights on the "high end" (none of these are inexpensive). There are other good ones out there, of course.

At any rate, if you have any idea of shooting past two hundred yards or so, you will need a good set of Vernier sights. I don't recommend the cheap Italian conversion sights. Pedersoli, however, does make a decent sight but you have to know which model is a good one.

Good luck and shoot center!

Dale53

Swifty, I've been shooting the B/C for about a year now, and it's a good rifle for the price. It's not legal for BPCR Silhouette, but is accepted in a few of the other classes. Mine likes the Lee 500 3R and the Paul Jones Creedmore with SPG lube.
Forget about lapping............probably won't need it.
Also, OAL info to touch lands:

  Lee 500 3R = 2.900
Paul Jones    = 2.910

Mine uses a vernier tang (5" elevation) inletted into the stock wrist and the Lyman 17A (.584")

Check over at Graybeard Outdoors; there's a ton of guys shooting and modifying them:

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Pedersoli, made for the 1874 Sharps. 2.260" hole spacing, windage adjustments, perpendicular adjustment.

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It's true the rifle isn't legal for BPCRS, and it's probably for about the same reason that bbls shorter than 21.5" aren't legal for ASSRA.

I.e., someone in authority decided, for whatever personal reason, that he didn't want it to be legal.
JMO, Joe

PS there has been some discussion about petitioning the NRA Silhouette Committee to make it legal, but nothing yet that I know of.