i accidently bought the wrong size bullet sizing die...

[mozeppa]

bought a die that sizes bullets to .310 for my ruger pistol ....and it made them too big. so i bought a .308 and all is good.

now i have a .32 acp pistol that uses .312 boolits.....how hard is it to lap out the .310 die to .312?

[Outpost75]

Probably .311" is OK for your .32 ACP.

Most likely bullets will come out of the .310 die a few tenths over so that you don't have to lap out very much. Measure some bullets sized by the die as it is, load some up at .310+ and give them a try in your .32 ACP. Don't lap the die unless you really need to.

[bmortell]

you didn't mention push through or another type. push throughs are very easy to lap bigger because it don't matter if its perfectly even, all that matters is the size of the smallest point. I always buy too small and make it the exact size I want. you need the ability to repeatedly bump a slug and push it through then mic it. and a hand drill, a rod with sandpaper wrapped around it. enlarge with 200-400grit sandpaper then 1000-1500 grit at the end to make it smooth. really only thing you can do wrong with a push through is go too big so this is why you must slug/mic frequently.

[mozeppa]

yeah.... i needed .312............ its an "ortgies" 7.65 mm (32acp) built before wwII really deep lands & grooves.
went ahead and tried.... i have a very small clock makers lathe ...and by coincidence i did what bmortell hit upon.

used 320 for about 20 strokes then used 600 for 20 ....followed by diamond paste for 10 minutes on a wood rod.

cleaned it with solvent ....put it in the press and rammed a pure lead round ball thru it .... and voila a perfect .312 slug popped out!

yay! ....don't have to buy one!

[mozeppa]

p.s. .....i have pin gages , mics ,calipers and a dozen other measuring devices.

and it is a "push thru" lee die.

[bmortell]

it would seem your over-qualified lol

[Outpost75]

Bravo Zulu! Nicely done.