You may not be getting sufficient chill hours for the varieties you're growing.

Are you getting blooms? If so, do you have bees around?? It might be a pollination problem..

I have 1 kieffer pear that does real well.2 orient that blooms in fall produces very little.

Some varieties of pears take too many years of growing before they are ready to produce fruit.One Mississippi, two Mississippi, etc., etc. Some varieties need too much cold Winter before they will produce fruit in your area.Sometimes pear trees flower in Summer or Fall instead of Spring because in Spring they did not have moist soil, and it started raining in Summer or Fall. Watering them to keep the soil moist is simple enough during the all-important Spring. You may want to check with your local County Extension Service for their recommendations on varieties that have worked well there. The 2 varieties that you are growing are sold at lots of nearby big box stores for low prices, but they are far from being the best pear trees to invest your time and energy in growing. At some point in the future, you may want to consider to try grafting some cuttings from better pear trees to the Keiffer and Orient branches. Good luck.

If you are in southern MS there is probably a lot of transfer value in the deep experience in pear growing (and finding/collecting) in the Houston and Harris County TX area.

"Tennousi" "Acres Home" "Meadows"

Plus "La Beauty" and "Leona" from LA I think.

Also "Southern Bartlett" "Southern Queen"

Do a bit of googling for > pears extension "Harris County" "Acres Home" etc.