update about marui mws blot lock problem, i have fixed it.
after my observation and the others opinions, i conclude 3 ways to solve the problem
Reason:
1) first production magazine--> the small spring in the mag follower is too weak, so it will cause the bolt lock problem
second production magazine solve this issue
2) as all know the the mws in japan use 134A gas, but the other use the top gas even higher, so the bolt lock plate have insufficient time to jump up under the top gas condition.
solution:
1) buy a stronger small spring
2) screw the stock tube with less round (more space for the bolt move back, so that increase the time for bolt lock action of the lock plate. also you can use the SA 80% recoil spring--> increase the recoil time, increase the recoil force, increase the gas efficient.