No!
Muzzle down tends to stay down due to the effect of gravity. I've NEVER had a muzzle down rifle end up pointing at me. Muzzle up rifles however wander in random directions above the horizontal and invariably end up pointing in someones direction, even if they are up to 5 km's away! If you plug you barrel or shoot yourself in the foot, then you have been negligent in muzzle awareness to yourself and deserve a Darwin award! Pointing your rifle in anyone elses direction is quite simply not acceptable!
MS
Your wrong MS...
Spend some time loading over 20 years at double gun days using shotguns. Then tell me that the danger of where a muzzle points can be eradicated by a particular way a gun is carried or handled. Its always down to the users awareness and this is something half a day on courses should be dedicated to IMO, not just a few minutes effectively.
There are some folk out there who have no clue about where a muzzle is when they stop to spy and lift the shoulders and arms with the Binos, chat, swing the gun off at the end if the days stalking and so on. I've had folk turn towards me with the muzzle down and it's ended up pointing at my knees. The muzzle never ever points straight down and at best I would guess 30deg from vertical. I don't care if its pointed at my face, feet, shoulder, knees its a life changing injury if it goes off.
Its impossible to carry a rifle here without it snagging on cover if pointing down unless its got a barrel of 10" and no moderator. And as for never plugging a barrel, if you've never slipped when out stalking on hidden branches or smooth rocks the ground your on must be very easy. I've gone up in the air before, last season in fact with the muzzle up and at least I knew when I came down and whacked the ground that muzzle was pointing away from the direction of my head and body. Carried down it could easily have been pointing at my feet...
To be honest every time this question appears it irritates me a bit because the actual carrying of the rifle should not matter in some respects, it's having complete muzzle awareness when the rifle is moved from that position, either deliberately to alter the direction the muzzle points in to take a shot, put away, hand to someone that counts as well as the movement of that muzzle by a change in your body movement, a non deliberate movement you can't avoid because of where your walking, stooping down etc.
I was sat in the back of a double cab pick up a few years ago waiting for the under stalker to return after a day helping out on Sika. A paying guest was in the front. As the young lad arrived back the head stalker asked if his rifle was empty. It was pointing at the ground just outside my door, within 1m of where I was sitting but pointing at no-one. It went off showering me in bits of stone from the track, in my eyes, mouth face. The guest started screaming he had been shot. I jumped out to find either a pice if bullet or stone had entered his welly where he sat in the front, gouged through his calf and exited through the roof of the cab. It was a relatively minor injury compared to what could have been.
Rifles with muzzle up
only wander about if the person carrying it allows it, just the same as if its pointing down and ends up at my feet or knees. Don't say
never happens in the shooting field, because it might just the next time your out.