Slug/Measure a bore

[M&PManiac]

All

I am a novice to boolit casting but have done some. I want to get a little more scientific in my approach to yield better results. It is apparent that measuring the bore of my firearms is an important aspect of effective boolit productio/casting. I am in need of how this is done and what tool(s) are required. Please advise.

[williamwaco]

Lets have some fun here.

99% of the time, slugging your bore is a complete waste of time and effort.

I never slug until I have tried at least a couple of different sizing dies and failed.


.

[runfiverun]

oh boy.
i'll confess I have never slugged a barrel.
it's not the area I worry about.....until I have to.

[.22-10-45]

With modern U.S. made firearms..the need for slugging is probably not necessary..those bores are held pretty close. However, if your dealing with 19th century rifles and revolvers when standards were pretty much what that particular company..or craftsman thought right...then there is a great deal of wisdom in slugging. There is an old saying about 19th century gunsmithing...soft lead and black powder covered a multitude of gunmaking sins!

[Taylor]

I do,and I find that it gives me a better starting point.

[MtGun44]

What particular guns? For some calibers there is a very high probability of
success with the "correct" diam. The guns that take measuring most often are
revolvers and then you are mostly making sure that it is made correctly and
not going to make it harder for success without measuring.

More info and we can probably help.

Sample info: For .45 ACP use .452, for .38/.357 start with .358, for 9mm
start with .358 unless a dummy round will not chamber, then use .357.
For .30 cal rifles, start with .311, for .45 cal rifles start with .459. If you then
fail, try LARGER first unless you have a chambering problem. Hardness is
a secondary or tertiary issue. Fit, design and lube are the issues of critical
importance.

Bill