There's four reasons nylon screws break off during a ....landing. One is that they were run down too tight and were ready to snap to begin with. Two is that the field is really rough and the gear is getting twisted and turned during a roll out. Three is because the plane is too heavy for the screw size. Four is because it wasn't really a landing, but a semi controlled crash.

Number four is the most common reason for breking nylon bolts on landing gear. Used to fly with a guy that came to the field with a bag of them. Every "landing[:@]" took the gear off. Eventually his planes had so much epoxy on the landing gear plate that they weighed almost a pound more than when they started. Pluds they looked pretty ratty after all the repairs.

Those that learn how to use the throttle to control altitude, the elevator to control airspeed, and use a standard downwind, base, and final landing pattern do better at landing. Don't drive the plane to the ground, but level off about a foot above the ground and lowly raise the nose as it bleeds off speed, permitting the plane to gently sink and finally stall into a nice, soft landing.

More simply put, if you really need "break away" bolts on the gear then you need to learn how to land a plane. You already know how to do a fairly level crash.