30-30 bullet sizing??

Sharktown · Post by **Sharktown** » Thu Mar 22, 2012 4:28 pm

I have finally slugged my Marlin barrel, it is a Microgrove barrel. The slug miked at .307 would you size cast bullets at .309 or .310? I'm using A Lee 150gr flat nose GC bullet mold. Since the rifle was rechambered to A.I. some years ago cast bullets would not make any difference at A.I. velocities would it?

Thanks - Sharktown

Terry Murbach · Post by **Terry Murbach** » Thu Mar 22, 2012 4:33 pm

OF COURSE IT WOULD. EVERYTHING MAKES A DIFFERENCE.

GO WITH THE LARGER O.D. IF THE CHAMBER WILL ACCEPT THEM.

Sharktown · Post by **Sharktown** » Thu Mar 22, 2012 5:12 pm

Thanks Terry for your advice!
I will try the larger sizing die and go from there.

Shatrktown

Tycer · Post by **Tycer** » Thu Mar 22, 2012 7:47 pm

Terry knows.

JohndeFresno · Post by **JohndeFresno** » Thu Mar 22, 2012 9:19 pm

Hello, Terry. Glad to see you back!

earlmck · Post by **earlmck** » Thu Mar 22, 2012 11:16 pm

Sharktown wrote:Since the rifle was rechambered to A.I. some years ago cast bullets would not make any difference at A.I. velocities would it?

Terry is right on the sizing. Your diffuguilties may come from the A.I. -- cast bullets are not fond of having any lube grooves extend down into the powder area. That's why the standard 30/30 is such a great cast bullet cartridge. With an A.I. chamber I'd be thinking of using lighter (shorter) bullet styles to keep this extension to a minimum. I'd sure start with pretty modest velocities also, just because my personal experience has been that boolets whose bottoms got cooked loose accuracy at lower velocities than uncooked ones.

Sharktown · Post by **Sharktown** » Sat Mar 24, 2012 8:49 am

Thanks everybody for your time, experience and suggestions. I am going with Terry's advice of getting a larger sizing die and work up loads from there and will post how the load development went.

Sharktown

Griff · Post by **Griff** » Sat Mar 24, 2012 9:16 am

Then too, of course, you can simply seat the bullets out further so that no grease grooves are exposed below the neck. At even std. .30-30 velocities, you should be using a gas-checked bullet to prevent leading. However, that may precluded from using a .310 sized bullet... as Terry sez, everything is dependent or bears a relationship to everything else.

Lefty Dude · Post by **Lefty Dude** » Sat Mar 24, 2012 3:31 pm

I would go with a .309 GC, and .310 barefooted. JMHO, you understand.

Most chamber/throats will accept a .310.

30-30 bullet sizing??

30-30 bullet sizing??

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