Firearm : Winchester Model 07 .351SLR Cartridge : 180gr Remington Soft-Point (index # 7435) Not a gelatin test - penetration depth is calculated based on expansion of bullet in water and velocity at impact. (MathCAD file attached) This was a water test, with the target consisting of two 0.5 gallon waxed cardboard Orange Juice jugs filled with water and placed front-to-back in front of the bullet catch box. Single shot impacted at 1787 ft/sec, expanded to 0.694" average diameter and was recovered at 157.5gr. Calculated penetration depth (in tissue) was 11.1". Now to the calculations - here is a screenshot of the MathCAD:

The MacPherson number was arrived at by a linear interpolation of Figure 8-31 in Bullet Penetration. To give a frame of reference, this bullet penetrated the 16.0" bullet catch box and one 1 gallon water jug placed behind it, after going through ~ 8" of water (which at this velocity range is equivalent to ballistic gelatin).