to be fair 99% of the bullets on the market use hydraulic force to make the bullet expand and what is going to make a bullet more violently expand then straight water (ok high pressure hydraulic oil might be more rapid). what might be a better test if you cant get gel is to take a media like clay and something that can be made into a paste and get it to 55%-65% water to match its water content to that of a animals body. given that most flesh is mostly water and protein, gelatin is without a doubt the best test. noslers are also usually designed to expand at fairly low velocities so that usually means slightly more rapid expansion at short range. in my opinion if a bullet can produce the same result every time it hasnt "failed", it has only done what it has been designed to. it wouldnt be the first time a bullet has been made to not pass through a animal in favor of a "expending energy" within the target. if the bullet doesnt meet your standards and you dont have dies for your 270 wsm maybe try a trophy bonded tip or a tipped triple shock