What is the best order of process for a new rifle?

[offhand35]

Hello, Veral!
I have read your cast bullet book over and over, but have yet to order anything else from LBT......
I have just obtained a brand new Ruger #1 in 405WCF, and want to shoot cast bullets with it from one of your molds.....
I would like to work it up for the bullet that will shoot best from it.  I have slugged the bore using a .495 lead round ball pounded into the muzzle then pushed through with a dowel. It measured .405/.412.   I found a very tight constriction at the point where the barrel threads into the receiver.

Do I first get your lapping kit and shoot some .411 240gr cast GC bullets for a 41 Mag to lap that constriction out, then re-slug the bore, then do a throat slug before ordering  a mold?

Thanks for your help. I am looking forward making this an LBT shooter!

[Veral]

  I think your constriction is probably at the sights or something farther up stream than the receiver, as the chamber is encased by the receiver.

  But you are now well aware that the barrel isn't perfect, and have a pretty good handle on procedure.

  Make a throat slug and order the mold, push through slugs and lap kit too if you don't have it.   Lap with bullets from the mold you buy until a fresh push through slug tells you the bore is perfect.  The bullet will be quite a bit over groove diameter, so as to fill the chamber better, which is most critical on straight wall cartridge rifles.