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Slugged barrel sizes
Posted: Sat Mar 19, 2011 4:42 pm
by ovenpaa
I slugged a couple of .303 barrels today and have the average results of:
Rifle one gives me a fairly steady .3120"
Rifle two gives me a fairly steady .31232
Are these acceptable tolerances and what range of cast boolit diameter is suitable?
Re: Slugged barrel sizes
Posted: Sat Mar 19, 2011 5:11 pm
by Christel
What's this "I"?
For the record, I held the rifles...
Re: Slugged barrel sizes
Posted: Sat Mar 19, 2011 5:48 pm
by Alpha1
They are OK you need a boolit sized to .313/.314 Lyman do a mould in .314 that I have had some good results with in .303 rifles.
I am asuming those measurements are your rifling groove size.
Re: Slugged barrel sizes
Posted: Sat Mar 19, 2011 6:17 pm
by ovenpaa
Yes this is from the slugs so will be into the groove. I have some of Dodyrog's .314" 190 grain cast boolits to use so I am off to measure my COAL next.
Re: Slugged barrel sizes
Posted: Sat Mar 19, 2011 7:08 pm
by Alpha1
Sounds like your into the groove m8 :lol: :lol:
Re: Slugged barrel sizes
Posted: Sat Mar 19, 2011 10:08 pm
by ovenpaa
Allowing a 5 thou jump gives me a build length of 2.880" with the 190's does this sound about right? This cast boolit lark is very new to me.
Re: Slugged barrel sizes
Posted: Sun Mar 20, 2011 7:57 am
by dodgyrog
I'm amazed you can measure to 5 decimal points! What kit are you using?
Good luck with the boolits.
Re: Slugged barrel sizes
Posted: Mon Mar 21, 2011 7:05 pm
by ovenpaa
I was using a Mitutoyo digital micrometer than measures to half of a tenth of a thou (And it is in calibration as well!) Such accuracy is quite pointless as the difference between a warm and cold day is measurable on a 25mm block of stainless.
Re: Slugged barrel sizes
Posted: Wed Mar 23, 2011 11:34 pm
by pe4king
ovenpaa wrote:I was using a Mitutoyo digital micrometer than measures to half of a tenth of a thou .
isnt that a gnats cock?, its been a standard unit of measurement as long as I can remember