Thanks to Larry Gibson and others I bought the drill kit that goes in a sizing die (Lee in my case) and tried this out on DWM 7.61x51 cases I have a lot of. The Berdan in them is .217".
I did it 2 ways. 10 cases each way.
1. Drill the new flash hole with the drill kit. Pry out the old primer. Deepen the pocket enough to accept a .210 Large rifle primer. Stick that in with your thumb. Put red locktite over it.
No problem with 220 gr cast @ 1500 fps.
2. Drill the new flash hole with the drill kit. Drill w/5/64th drill through the hole in the primer, from the outside, deep enough to seat a small rifle primer. Swage a new pocket from the remains of the Berdan using a SR pocket swager. I used RCBS. Put a SR primer in using your press. No problem with 220 gr cast @ 1500 fps.
On an earlier thread I noted problems with the drill kit. The kit comes w/no instructions. The kit has a moveable sleeve the drill rides. Once I figured out the sleeve had to be adjusted to its lowest setting, the drill centered up fine and worked perfectly.
As much as I like this beautiful DWM brass, I just bought 500 fully prepped 7.62x51 LCNM cases soo -----
This is a useful process if you have brass that is unavailable in Boxer primed.