Ron Guth:
The Mint used only two obverse dies to strike Half Dimes in 1803: a Small 8 in the date, and a Large 8. The difference between the two is immediately apparent by even a casual visual examination, but the best way to tell is by looking at the size of the 8 relative to the 1 of the date. On the Small 8, the 8 is smaller in height than the 1 and on the large 8, the 8 is much taller than the 1. Because of the rarity of the Small 8 variety (JR-1), you are most likely to run across a Large 8 variety (JR-2 or 3), but it is still important to check if you are not sure.