303 bullet size

[gtpkeeper]

measure the inside of a fired ppu case it mic at .313 so thinking ill need aleast that size in lead ??

[MikB]

measure the inside of a fired ppu case it mic at .313 so thinking ill need aleast that size in lead ??

That has little or no bearing on the bullet size needed. The casemouth will have been blown wider as the bullet was driven out and up the bore, then sprung back part of the way - practically impossible to know how much, unless you know the chamber neck i/d and the exact case wall thickness.

[gtpkeeper]

That has little or no bearing on the bullet size needed. The casemouth will have been blown wider as the bullet was driven out and up the bore, then sprung back part of the way - practically impossible to know how much, unless you know the chamber neck i/d and the exact case wall thickness.

Ok so what size do you think

[lightning22]

When you say you've slugged the bore, what method have you used?

[gtpkeeper]

When you say you've slugged the bore, what method have you used?

hi
first tap lead ball down the muzzle ,
second one from chamber side

[lightning22]

hi
first tap lead ball down the muzzle ,
second one from chamber side

If you are putting the calipers across the 5 groove rifling impressions you will be getting a larger diameter than it actually is. There is a way of doing it with V-blocks but for sizing for cast you need an accurate throat diameter.

I use the pounded or impact slug method described below, taken from the Cast Boolits archive.

Another alternative (prefered by 45 2.1) is a pounded slug. One fills a fired case with a hard lead alloy leaving just a little of the neck empty, and then drives a soft lead slug into the lead/case/throad area. Using a brass rod of near bore dimensions if the best driving road. There are other ways to get the same pounded slug, but this is the way that worked best for me. Lube the bore and outside of the case and use a heavy hammer to pound the slug into shape. there is no shrinkage doing it this way.

[gtpkeeper]

already put slug down the chamber into the rifle , its 2 band , then remove slug i measured the two bands that were stcking out ...and got the reading of ,318

[loiner1965]

Ok so what size do you think

.314 gas checked and lee alox lubed

[waterford103]

I'm done with casting lead bullets , done way too much , I buy bullets for my 303 from dodgyrog sized exactly to my bore , my bore is 313" and in good condition so I buy .314 bullets . Don't shoot lead bullets after jacketed without de-coppering the bore scrupulously , if you fail to do this any groups you achieve will be of the shotgun variety.

[gtpkeeper]

cheers guys for your help,
whats best for removing copper then

[lightning22]

I use Boretech Cu+2