>>64165628
I don't think it'd work easily, part of the M1's fast reload is that the en-bloc is short and can be easily handled and oriented with your one hand, also being able to load it 'upside down'.
The other part is that the action locks open and spits the empty clip out for you, so you don't need to manually remove it, just slam the new clip in and let the bolt home.

H&K's prototype HK36 rifle (not to be confused with the much later, and decidedly more sane and conventional G36), was a roller-delayed assault rifle with a LRBHO.
It had this pretty wild idea where the magazine was fixed to the rifle and it would be loaded with 25rd plastic packets/clips, also using a proprietary 4.6x33mm rifle cartridge with a bizarre 'spoontipped' projectile.
The HK36, if it had been designed for the 5.56mm instead (which was much better at penetrating armor, part of the 4.6x33mm's demise), and if the cyclic rate had been halved to a more sane 600rpm (yes, the HK36 honest to god had a 1200rpm cyclic rate), could maybe have been a more appealing prospect, along with adding proper irons.

The HK36 did not spit the plastic clip out for you when the bolt locked open, I think, though it might have been designed to plop out an empty clip once you opened the magazine door. Not sure, there's VERY little information on it (it's entirely possible that there was only ever one single prototype which was gradually iterated on).

tl;dr it's an idea which has at least been played with, though it's very unclear how well this actually worked.