50%-60% is about right for silage.
You can make it wetter, I've put up grass silage which was direct cut by the chopper and then ensiled. Very wet and smelly but the cows loved it.
Too dry and it doesn't ferment properly.
As a homesteading sort I've put up both hay and corn silage in plastic garbage bags.
The hay silage was actually lawn clipping we swept up and ensiled the day after mowing(just like I would do with good hay silage). However grass is a lot drier overall than a good lush hay field and I would mow in the morning and put it up in the afternoon if I had to do it again.
The corn silage was a mix of old sweet corn that didn't get picked and some field corn we planted just for the occasion. Cut it with a corn knife, stacked on a wagon and hauled to the shed for processing.
As for the process, I live in a very cold area and have spent my share of chore time chipping frozen silage off a silo wall. So I decided barrels were out. No sense have silage that I couldn't get out of them because it was frozen in.
I went with heavy duty garbage bags. With the hay silage I also had access to 30 or so 5 gallon buckets with lids so we poked and stuffed the bags full in the buckets, taped them shut then put the lids on. It was drier stuff but it fermented OK, just didn't have the texture I was looking for. The goats loved it though.
For the corn silage I started out with a small chipper and quickly decided that something else had to be done so I bought a real forage chopper body cheap (it was small by todays standards) and used that.
With the chipper the outlet is right down by the ground so you are constantly moving the chipper or forking as fast as you can. With the chopper I blow a bunch into a foldable plastic pallet and when that's full I start filling bags.
As for the bags, corn silage is not as soft and fluffy as hay silage so I fork old feed sacks full, then tamp, smack, beat and in general treat them with disrespect until I can get no more corn in. Then I put that sack in a large garbage sack and apply vacuum from an old upright that the wife no longer uses. The whole package shrinks down to less than half size. Twist the plastic garbage bad and tape with duct tape.
Next year I may try putting two feed bags into one garbage bag after vacuuming them.
Mice are a problem with the corn silage, I lost a few bags to the critters. And I mean lost, they took every thing and left the plastic.
If you do a barrel I have seen plans for building a hydraulic pusher to squeeze it full. Or you could build a stand with a big lever and a pad, similar to a homemade pine needle baler.
The key is getting a good pack, upright silos have tons of feed doing that, bags have a bagger that pushes the stuff in, bunkers use tractors or crawlers to do it......
Here is my rig for doing silage, you can see the old chipper in the background. The chopper is modified a bit. The spout is not stock, it's far shorter, I believe it is an old spout from some silo pipe. The cardboard barrel directs the stuff into my pallet.