After opening the rifle case & inspecting the rifle I was highly impressed with the case-hardened receiver & the beautiful finish of the metal & wood. And the mating of the receiver & stock is amazing. I hope I never have to pull the stock off. When inspecting the muzzle my 1st thought was they forgot to crown it. But a close inspection indicated it was indeed crowned but with the thinnest crown I’ve run across on a firearm. Looking very close I could see the slight uniform taper on the ends of the lands.
So, prior to shooting a firearm, especially one requiring hand loading, I always check the bore twist; make a chamber cast using Cerrosafe & closely measure the chamber & throat dimensions at the correct time after the cast is poured. See the photo of the cast below. Here’s what I found:
Working from the chamber breech to the throat:
Rim seat depth (rim recess): 0.070”
Rim seat dia: 0.607”
Headspace: 0.071”
Chamber dia. (inside case rim): 0.502)”
Chamber length (inside case rim): 2.040”
Overall case length: 2.100”
Chamber mouth diameter: 0.4325” (see note 2 below)
Chamber transition length: 0.013”
Chamber transition angle: 45.0 degrees
Freebore length: 0.025”
Freebore diameter: 0.409”
Leade length: 0.075” (see note 3 below)
Leade angle: 2.5 degrees (see note 3 below)
Bore (land) diameter: 0.4005”
Groove diameter: 0.4070”
Land height” 0.0035”
Notes:
1) Bore: 14.5:1 right-hand twist, 6 lands & grooves, lands: 0.070” wide, grooves: 0.140” wide
2) There’s no evidence of a well-defined neck. I.e. the chamber has a uniform taper from the breech to the chamber mouth.
3) The lead length & leade angle are very hard to measure with vernier calipers or other instruments I have available. Therefore the dimensions are an estimate.
Wayne
