The Griffin & Howe or Paul Jaeger side mounts are superior to the Pachmayr swing mount, but they are heavier. They let you slide the scope off the rifle entirely. They are very stout, so you can use them on .375 H&H, etc.
But even better removable mounts have been designed since the 1970s.
Recknaler pivot mounts, which were offered by Steyr on their Models SL, L, M, an S, have a very low prismatic base, which the rings sit onto, instead of into. Expensive.
EAW pivot mounts, offered by NECG, have rings which sit into a heavier base, and pivot into the rear. They have the advantage of offering an aperture sight which snaps into the rear base. Expensive.
Talley has their own dual flat bases, which their rings clamp to with a lever. They also offer a rear peep sight.
Warne rings clamp to a Weaver, Picatinny or their own bases.
Leupold QRW rings clamp to a Weaver, Warne, Picatinny or their own bases.
Leupold QR rings rings plug into their own bases an lock with a can by a small lever. These are stronger and lighter than the QRW rings.
