Ok, I've yanked the cover off and I'm ready to rock and roll. But now I want to safe my rifle so I can sling it over my back, time to fumble for the little trigger cover! That is... If it hasn't been lost.
At least the way I'm imagining your idea, it doesn't seem as simple or as fast as having a manual safety in a good location that I can quickly flick on or off.
As far as putting it on firing inhibit for slinging goes, there are 3 reasons why I would sling the rifle.
- The fight is over.
- There is a malfunction.
- It is out of ammo.
If the fight is over, I have all the time in the world to put the trigger cover back on.
If my rifle had a malfunction or out of ammo, why do I need to put the rifle on firing inhibit?
Also, your argument reveals that you are either not aware of or forgot that most combat rifles, like AR-15, does not even allow you to "on safe," putting the rifle selector in firing inhibit mode when you discovered there is a malfunciton or the gun is empty after a trigger pull.
So, slinging the gun with the selector swich on "semi" is a non-issue even for an AR-15, not just a rifle designed the way I want.
There may be some situations where I would sling the rifle when I do not have a malfunction and the gun is not empty, but that would be when I am not under direct attack. If I am not under direct attack, I do not see why I cannot take some time to put the trigger cover back on, just like a person would holster a pistol when the person needs both hands for something while not having to shoot. If I just to happen to be in a very limied scenario of slinging my rifle when it is not out of ammo or in a malfunction state while under direct attack for whatever reason, then I will just do what I need to do, even if it means slinging a firing enabled rifle. It is a calculated risk.
I also doubt you are going to argue that no one should use a Glock or M&P on the grounds that the holster might get lost.
Also, I tried a version of a holster below, and it works very well. I do not find it dubious at all.
http://www.rcsquickship.com/