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View Full Version : Sizing for Throat Question - at dimension or under?



Rfeustel
08-24-2021, 06:13 PM
Hello Boolit Buddies:

When sizing a cast boolit for the throat, do I size for the same dimension of the throat, or do I size for .001 less (or something)?

Thanks

Cosmic_Charlie
08-24-2021, 06:36 PM
Size so that the boolit will push through with some resistance. I have found a loose fit to be better than one that won't push through. My loads tend to be around 1000 fps and a bhn of 10 works well.

Mal Paso
08-24-2021, 11:13 PM
Just push through. I think my goal is .0003" under throat.

charlie b
08-25-2021, 10:06 AM
I like to be .001" over the groove dia. That should be slightly less than the max throat dimension.

Char-Gar
08-25-2021, 10:50 AM
Are you asking about rifle or revolvers? Different answers.

DougGuy
08-25-2021, 10:56 AM
I like to be .001" over the groove dia. That should be slightly less than the max throat dimension.

With a revolver, that would be more often than not after honing throats...

Centerfire revolvers work great with boolits sized .001" or .002" greater than groove diameter, throats sized .0005" to .001" greater than boolit diameter, so you have a push through with the fingers fit in the throats with light drag. Semi auto boolit diameter .001" or .0015" greater than groove diameter, throat .0005" greater than boolit diameter.