The Midcap VFC QRS M4 magazine is currently one of the best magazines out there
available for the M4 replicas.
The Magazine is suitable for most M4 Models.
The magazine is made of Polymer which makes it very strong but also very light. The structure
gives the magazine a good grip when it comes to reloading.
Note that with every magazine it can happen that the BB's do not feed properly on a certain brand of replica.
The advice is to try a different brand of magazine, in order to solve the problem.