Lyman Chiappa 38-55, no lands?

[MC One Shot]

Tonite I made a chamber and bore casting of the wife's Lyman 38-55 mini Sharps by Chiappa. The casting appears to show that there is minimal to almost no rifling.The dia of the casting is .379-.3805 taken 1 hour after casting. There was not enough riflling for the most part to catch a finger nail on.

Has any one else taken a chamber/bore casting of the rifle in the same caliber and found similar results?

Plan on redoing the cast as well as doing a muzzle bore cast tomorrow and compare.

[Goatwhiskers]

'Spose you could have such a factory defect. On the other hand I have seen one rifle that was so leaded that you couldn't find lands or grooves. If you're using Cerrosafe it's not hot enough to melt the lead out of the way. Just food for thought. GW

[MC One Shot]

Did not see any leading before hand. Just cleaned for lead just to be safe, no visible lead particles. Will have to see what tonite brings when I recast.

[country gent]

DId you warm the barrel chamber with a hairdrier or heat gun? cerrosafe is liquid at 180* or so and a room temp barrel could cool it before it fills in grooves completly. Heavy oil or grease could cause this also.

[Don McDowell]

that's .015 difference, or .0075 per groove, that's about normal.

[GabbyM]

Did you measure the slug groves?
Most people can only detect about .0013" with a fingernail. Thus when you say you can barely catch a fingernail. you could easily have a .003" deep rifling. A sheet of 20 pound copy paper is a tad over .003" btw.

[Bigslug]

I'm a relative babe in the woods on the topic, but you might try a pure lead pound cast of the throat. That'll probably get you closer to the true dimensions. I helped do this on an original 1885 .38-55, and while age and wear were obvious factors, the rifling was obvious not all that deep to begin with.