hey loaded some up an ran into an issue, with the lee 303 brit fls die, once i seat the projie, it strips off the rings of the cast!
And that means numerous things. First, you've purchased bullets that were spec'd at something like .313" if I remember correctly. And you've resized your cases in dies that prep the necks to have an interference fit with jacketed bullets at .311" diameter - I'm guessing the I.D. of your case necks after sizing will be something like .309" - .310".
See what's going to happen here when you seat those .313" bullets after having done nothing but resize the cases? Especially when you almost certainly didn't put any flare in the case neck?
So you have a couple of solutions available.
First, you can buy some variation of case flaring tool to flare the case mouth. Lee has a universal case mouth expanding die, but that's pretty crude. You can flare the case mouth enough so it isn't cutting shavings off the bullet when seated, but once the bullet gets past that flare, it's being seated into a neck that is still sized to take a jacketed bullet .002" smaller. Pull a couple of bullets after you've seated them that way and see if the bullet has been sized down a bit after doing that.
Second (and in my opinion the best), you can use the Lee collet neck sizing die, which also provides all kinds of other advantages. Send Lee a few dollars and they will sell you a sizing mandrel of the size that is best for your bullet size that fits your ball seat/leade. So, if after measuring a cast, you decide that a bullet measuring .313" is the best fit for your rifle, purchase a mandrel that will size your necks to .312". And (or alternately) purchase NOE's really slick neck expander tools.
Each size button costs only a couple of bucks, so you can experiment with changes by .001". Those buttons will both expand the neck AND put a small flare at mouth to ensure there's no cutting. They don't eliminate the cold working of the case each time you resize your case like a collet die does, however. I resize with the collet die and use the NOE button to put a miniscule flare at the case mouth. It takes only a few extra seconds when doing your case prep, and if you're using a collet die for sizing, you save the time you used to spend lubing cases and then cleaning them afterwards.[/QUOTE]