What do you mean by Strong ?

If you could expand further the reasoning behind your
question this would help us answer it.

In terms used in the DR field, the Holland Domimion Sidelock
is well known as one of the strongest.

The Webley "Screw Grip" or "Treble Grip" and Webley PHV1
Boxlock Actions are known to be very strong.

500 Nitro