I tried the 185gr Lehigh bullets in my 14 inch stock TC barrel in .375 Winchester with R-7 and it will shoot .5 - .750 inch 3 shot groups at 100yds. Still can?t believe it out of a stock TC barrel but it keeps doing it. I will have to try the heavier bullets in a few things. I shot a nice doe this year, close shot but it only went 10-15 yards. I also found they shot a just little better out of my .375 Without expanding the case mouth. The tapered base just slides right in.