Why is My Blank Gun Not Working

One very common reason a blank gun may not be cycling the shells properly is because the owner has removed the barrel restrictor plug. People usually do this to make the barrel opening look more realistic but the barrel restrictor is a necessary component to increase the back pressure allowing the slide to cycle fully to the rear position so it can eject and pickup a new shell.

The blanks you are using may not have enough gun powder in them. Some blank guns require banks with more gun powder than others, again this additional internal pressure forces the slide all the way back, if the blank does not have enough gun powder in it then only a partial slide motion happens and so the discharged shell may not eject properly, in this case the user would have to clear the blank gun manually so another shell can then be picked up and loaded into the breach.

Read full article here:
https://www.replicaairguns.com/2016/12/15/why-is-my-blank-gun-not-working.html