Low energy separated beams into very large bubble chambers, such as the Argonne National Laboratory 12 ft chamber, will have the consequence that many of the secondary particles will be magnetically trapped within the chamber volume. We show that for a highly uniform magnetic field, the turning angle of the tangent to a track of known mass, taken from production to stopping, provides visual estimates of the range to stopping, the total momentum, and the in‐flight decay probability. We also show that these estimates are independent of depth in the chamber and orientation in the magnetic field, and can be obtained for any view projection in the presence of optical distortions.