Slugging a Barrel?

[prickett]

This is probably a stupid question, but how can I measure a slug run through my barrel? The way my rifling is results in a land being directly opposite a groove. So, when trying to measure, I'm only getting the height of one land, not both.

[462]

Prickett,
An odd grooved barrel makes measuring a bit difficult. There are a number of ways to do so, this is mine. With the jaws of the micrometer fairly close to the boolit, rotate the boolit while slowly turning the spindle until you feel the slightest bit of resistance. If you pay attention, you will feel the two high spots. Go slow, do not apply a lot of spindle pressure as it will distort the boolit.

[mooman76]

Wrap a thin piece of metal aroung the bullet( like bear can ) and measure and subtract the difference.

[Buckshot]

............An alternative. At the muzzle, as close as you can get measure the OD of the barrel. Say it's .585". Now silp the tip of one caliper jaw into the barrel so it's in a groove. Now close the other jaw against the outside of the barrel. Again, the jaw inside the barrel should be 'just' inside. We want to eliminate any error due to the barrel's outside taper (if any). So we get a measurement of .1375"

Double the wall thickness (.1375") we just got = .275". Subtract that (.275") from the barrel OD (.585") and we get .585" - .275 = .310". Use the same proceedure to check for the bore ID also. Please note that if it's an old milsurp there may be some cleaning rod wear at the muzzle. To be as accurate as possible you can measure each groove and hopefully the bore will be centered in the barrel and you'll get the same reading.

................Buckshot

[prickett]

Thanks for the techniques guys!