A few years ago I used Winchester Supreme Partition Gold hollow point 260-grain slugs in my 20-gauge Thompson-Center TCR-87. When Hornaday came out with their pointed, plastic tipped 250-grain SST slugs I switched to them thinking that even if they were 100 fps slower at the muzzle, they would probably be better at long distances because of their plastic point. Today I finally shot both these slugs through my chronograph. I did this at 4 yards and at 52 yards and used this data in my ballistics program to calculate muzzle velocities, ballistic coefficients, and ballistics tables for both types of ammo out to 200 yards. My gun has a custom 24-inch barrel and a 2-3/4 inch chamber and tests were conducted at about 1,000 feet above sea level. The Hornaday SST slugs shoot more accurately in my gun and according to my ballistic tables have significantly more velocity and energy at long range.
The measured velocities of six SST slugs at 4 yards ranged from 1,721 fps to 1,822 fps and the measured velocities of three SST slugs at 48 yards ranged from 1,633 fps to 1,674 fps. Modeling this on my ballistics program indicates a ballistic coefficient of 0.287 for the Hornaday slugs and a muzzle velocity of 1779 fps. The advertised velocity of these slugs is 1,800 fps (pretty close). My ballistic chart indicates their down range performance to be significantly better than advertised. For example, Hornaday data shows 815 ft-lbs energy at 200 yards but my data (for 1,000 feet above sea level) shows 1013 ft-lbs. Note that there is a lot of scatter in the velocities and the limited amount of data could negatively affect the accuracy of the ballistic table which I generated. A lot more shooting would provide a better data base but these slugs are expensive.
The measured velocities of four Winchester Supreme Partition Gold hollow points at 4 yards ranged from 1,670 fps to 1,915 fps (nearly 250 fps) and the measured velocities of three Winchester Supreme Partition Gold hollow points at 52 yards ranged from 1,582 fps to 1,597 fps. Modeling this on my ballistics program indicates a ballistic coefficient of 0.182 for the Winchester slugs and a muzzle velocity of 1,781 fps. The advertised velocity of these slugs is 1,900 fps (not real close in my opinion). My ballistic chart indicates their down range performance is not as good as advertised. For example, Winchester data shows 1,260 ft-lbs energy at 125 yards but my data (for 1,000 feet above sea level) only shows 1,063 ft-lbs. Again, there is a lot of scatter in the velocities and the limited amount of data could negatively affect the accuracy of the ballistic table which I generated. And again, a lot more shooting would provide a better data base but these slugs are also expensive.
I have killed a deer at over 190 yards with the Winchester slugs and a couple at just over 200 yards with the Hornaday slugs. However, 175 yards may be a better range limit even for the Hornaday slugs, so here are three comparisons for 175 yards. With a 150-yard zero the Winchester slug’s trajectory is within 3.6 inches of the crosshairs out to this distance and the Hornaday slug’s trajectory is within 3.0 inches (pretty close). My ballistic table shows 867 ft-lbs energy for the Winchester slugs at 175 yards compared to 1,085 for the Hornaday slugs. That is a 25 percent energy advantage for the Hornaday slugs! The difference in wind drift is also significant. For a 10 mph crosswind at 175 yards my ballistic table shows 11.2 inches of deflection for the Winchester slugs but only 6.8 for the Hornaday slugs. That can be important in Iowa!
