Hi thee to your friendly Gun Shoppe and order the RCBS / Lachmiller Berdan decapper. These are a VERY nifty tool and, once set correctly for the particular case-head / primer size, will cheerfully dig out any lightly crimped primers with ease, without mangling the all-important anvil in the primer pocket.

MUCH less messy than any of the "hydraulic" methods. Hydraulic " is, however, about the only way to fly with anything heavily crimped in. Once you have the primer out, it is a simple matter to cut or swage the remnant crimp out of the way and "re-throat" the primer pocket.

In the only video I could find on line, the "presenter" is doing it all wrong, hardly a good a "wrap-up" of the equipment. Most of the comments are fairly snarky; "why would you bother", etc. One answer is cost, the other relates to really eccentric types who ONLY have Berdan-primed brass for their exotic Britishicon and European Big-Bore hunting rifles.

The RCBS decapper is not exactly a cheap piece of gear, but what is these days?

I am half-way through "re-cycling" yet ANOTHER 4-gallon drum of BERDAN primed 7.62 NATO cases (Singaporean, I believe), A bit boring, but the price of the brass (scrap-prices) was too good to pass up. A lot of the Australianicon-produced (MF / AFF / ADI Berdan primed stuff is LUDICROUSLY heavily crimped and the RCBS tool will have a very short life on a steady diet of them. However, Swede primers seem to be relatively lightly staked / crimped in. Un-crimped primers like you find in a lot of steel-cased ammo are a walk in the park. Given the extortionate cost of ammo and components over here in Oz, a lot of us will go to what seems to our 'merican cousins, a ridiculous amount of effort. It has ALWAYS been that way.

As for primers, you will need a .217" job. Vihtavouri / Kemira (No. 3) make one, as do our Russianicon cousins at Murom (KVB-7). Some quiet little shop MAY still have some of the excellent RWS 5608 or 5627 in stock.

I've been doing this sort of thing for over forty years; you too can be a true eccentric among peers.