I don't really know what you mean by too weak. There are two springs in a Trommel mag. One is a captured spring that is loaded by turning the handle one turn and locking it in its recepticle. The other one is a long coil spring (2ft?) that actually pushes the cartridges up the magazine. If the captured spring has been preloaded, then the coil spring will not feel too strong. When the captured spring is released, like when the mag was loaded, the coil spring will have a lot of force behind it and feel alot stronger. I, my self have disassembled these mags several times....dealing with the coil spring to get it back in is a bit of a bear. I don't know anyone who makes replacement springs, except Wolf, and you would have to give them all the dimensions...or the old spring.