The 742 is bought cheap because it's made cheap. The receiver is a mild (ie soft) steel and wears quickly. You can try stretching the springs (only a small amount) and see how things work. If it does, go to Numrich and buy replacement springs. I'm not holding my breath on that working, though. Pass it off on someone, and invest in something higher quality.
"I'd rather die on my feet than to live on my knees." E. Zapata