Customizing the Lee sizing die

BJung · October 1, 2020, 09:21 PM

The bore on my Arisaka meaasures .31105 and the Lee sizing die is .311. I need .312. Would you suggest I size to .311 and PC to .312, PC to .312 to .313, or use valve grinding compound to enlarge the sizing die to .312? I was thinking of using the same ram rod and put valve grinding compound on it or a bullet and drive it through the sizing die a few times.

dahermit · October 1, 2020, 10:11 PM

Quote:

Originally Posted by burbank_jung

The bore on my Arisaka meaasures .31105 and the Lee sizing die is .311. I need .312. Would you suggest I size to .311 and PC to .312, PC to .312 to .313, or use valve grinding compound to enlarge the sizing die to .312? I was thinking of using the same ram rod and put valve grinding compound on it or a bullet and drive it through the sizing die a few times.

I would be concerned that the grit size of valve grinding compound may be too big to use for your purpose. If you decide to go ahead and risk your Lee die, I suggest starting with some way finer abrasive. https://www.midwayusa.com/product/1006412014

reddog81 · October 2, 2020, 07:11 PM

Either method will work. I’ve done both. I’ve used 600 grit valve lapping compound to open up a sizing die. Just apply some of the compound to a few bullets and size them. Check the resulting diameter often. The Lee did only took a handful of passes to enlarge. I tried the same thing with a Lyman die and it took much longer.

BJung · October 3, 2020, 12:55 PM

Thanks reddog81!

5whiskey · October 11, 2020, 01:20 AM

I too would hone the die some. I’m a fan of sizing being my last step before loading the projectiles.

res45 · October 11, 2020, 05:46 AM

How to hone a Lee sizing die.

http://www.castpics.net/subsite2/How...Size%20Die.pdf

If you have any of the Lee Breech Lock presses you can use the Lee Breech Lock sizing kit

https://leeprecision.com/bl-bullet-sizer-kit.html

Then purchase which sizer you want to use.

https://leeprecision.com/breech-lock-bullet-sizing-kit/

Most all military type surplus rifle that I have come across will chamber a much larger dia. bullet than the groove to groove dia. of the bore, with a few exceptions. In general, I size my bullets .002" over groove dia. or as large as will easily chamber. Powder coating will add .002" at a minimum usually more depending on the thickness of the coating.

October 1, 2020, 09:21 PM	#1
BJung Senior Member Join Date: December 5, 2019 Posts: 773	Customizing the Lee sizing die The bore on my Arisaka meaasures .31105 and the Lee sizing die is .311. I need .312. Would you suggest I size to .311 and PC to .312, PC to .312 to .313, or use valve grinding compound to enlarge the sizing die to .312? I was thinking of using the same ram rod and put valve grinding compound on it or a bullet and drive it through the sizing die a few times.

October 11, 2020, 01:20 AM	#5
5whiskey Senior Member Join Date: October 23, 2005 Location: US Posts: 3,652	I too would hone the die some. I’m a fan of sizing being my last step before loading the projectiles. __________________ Support the NRA-ILA Auction, ends 03/09/2018 https://thefiringline.com/forums/sho...d.php?t=593946

October 11, 2020, 05:46 AM	#6
res45 Senior Member Join Date: September 15, 2007 Location: NC Posts: 753	How to hone a Lee sizing die. http://www.castpics.net/subsite2/How...Size%20Die.pdf If you have any of the Lee Breech Lock presses you can use the Lee Breech Lock sizing kit https://leeprecision.com/bl-bullet-sizer-kit.html Then purchase which sizer you want to use. https://leeprecision.com/breech-lock-bullet-sizing-kit/ Most all military type surplus rifle that I have come across will chamber a much larger dia. bullet than the groove to groove dia. of the bore, with a few exceptions. In general, I size my bullets .002" over groove dia. or as large as will easily chamber. Powder coating will add .002" at a minimum usually more depending on the thickness of the coating. __________________ The Reloaders Network discord Channel https://discord.gg/Nafuzht

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October 2, 2020, 07:11 PM	#3
reddog81 Senior Member Join Date: October 16, 2014 Location: Iowa Posts: 1,634	Either method will work. I’ve done both. I’ve used 600 grit valve lapping compound to open up a sizing die. Just apply some of the compound to a few bullets and size them. Check the resulting diameter often. The Lee did only took a handful of passes to enlarge. I tried the same thing with a Lyman die and it took much longer.

October 3, 2020, 12:55 PM	#4
BJung Senior Member Join Date: December 5, 2019 Posts: 773	Thanks reddog81!