To try conclusions

to make a trial or an experiment.

See also: Conclusion

References in classic literature ?
The Sheriff himself was not anxious to try conclusions again with Robin in the open.
All this the gentleman was observing, and with astonishment, more especially when, after having wiped himself clean, his head, face, beard, and helmet, Don Quixote put it on, and settling himself firmly in his stirrups, easing his sword in the scabbard, and grasping his lance, he cried, "Now, come who will, here am I, ready to try conclusions with Satan himself in person!"
One of history's most brutal butchers, now perhaps in his seventies, had set out with an army 200,000 strong from Samarqand, his capital, to try conclusions with the Chinese Empire, 3,000 miles away.