So I've been working on my pulllups for around 6 months now at my gym on one of those assisted machines.  I would do as many as I could unassisted (3-4) and then start using the assist for the remaining sets and do that 2-3 times a week.  Felt like my workouts were at a good effort level, but I never really improved.

3 weeks ago I got one of those door-mounted pullup bars and started doing them a lot more often and since then I've upped my max to 5-6 reps and my perceived effort has dropped noticeably.  It's weird cause it initially felt kind of awkward with the narrower grip, but I can't disagree with the results.

So then the question is what changed?  Having at home means that I can do a lot more spread out over an evening vs 15min at a gym, but maybe the Assisted pullups were holding me back too?  Are the muscles really able to develop when they aren't performing at "full" weight?  Any insight on this?

I've seen my biggest pullup gains doing max reps 3-5 times per day.

you have been working on pullups for 6 months and only increased your max by 2-3? Something's fucky.

I have always worked out at home & kept it simple, going to the gym is a pita (unless you use it as a social event) & any workout you don't keep up is a waste of time as when you stop you will get fat fast.

That's my point.  I'm thinking that the assisted pull ups weren't really doing much.  My only real gains occured in the last couple weeks.

Do more wider grip lat pull downs. That will aid greatly in pull up ability, and yeah IMO the assisted machines are garbage the grip options at least at the one at my gym aren't natural at all and adds more strain to your shoulders.

Back at the Air Force Academy, the PFT's first event was the pull up.  Min pull ups for men was 7.  Max was 21.  I would max it out every time.  On one PFT, the grader/scorer guy lost count.  My buddy later told me I did 27.  That's 27 real pull ups.  Not that cross fit bullshit.

Anywhooo...my point was during basic cadet training we had to do pull ups before entering the mail room and the mess hall.

So maxing out to fatigue 4 times a day is what really got my total numbef of pull ups up..

I have never done an assisted pull up machine.

I am not real keen on seated lat pulls either.

This is just like the bands people use for pull-ups, and I think this is the problem-

It's supposed to be hard, even when you increase on a squat 1RM it was hard before, but you're still capable of a few more pounds.  With the bands/assistance people simply don't increase the weight/decrease the help and they never progress.  You can bench 225 for the rest of your lift if all you do is train to bench 225, but if you progressively overload yourself you will grow in strength.

With the bands and assisted PUs, it's still hard so people simply don't try for more (or less help, in this case).  Tell yourself you are going to decrease 10lbs of assistance every week and you'd still get better.  Ride the same weight each week?  No change.

Or maybe wear a weight belt or weighted vested for 3 or 4 pull ups that you can do now.

Then like two weeks from now take off the weight belt or vest, and I bet you could then do 5 or 6.

I also did an Army training program called Air Assault.  They had permanent pull up bars installed by the barracks/quad area, so every time you either entered or left the barracks you had to do pull ups...if I am remembering correctly.

I guess in a way it is like Matthew McConaughey saying he does 1,000 crunches per day.  He doesn't do all one thousand at one time.  He breaks it  over the course of the day.  And he's a skinny looking fucker with 6 pack abs that the women swoon over.

Frequency + intensity

The "grease the groove" method is very effective for bodyweight motions, as you've discovered.

Bands and the machines both suck a huge floppy one for making you better at pull ups. If you can't get a clean rep, do slow negatives by jumping or climbing to the top position and controlling the descent. If that's too much, prioritize the upper back and biceps with lower to moderate rep strength work.

Bodyweight stuff, you want frequency but not intensity. More sets with a couple reps left in the tank works better for most.

That's what I was going to mention.

When I could do multiple sets of almost 20 pullups, I was also doing them almost every day. The pullup bar was right in a main doorway in the house.

Bodyweight exercises are cool like that, you can get very good at them in a very short period of time if you do them a lot.

My workout goal used to be 50 pullups, in as many sets as it took, after a few months it was only taking 3 sets to get there.

Thinking about it more, I believe that the same idea applies to other lifts, too, although probably not to the same extent. Lots of Olympic lifters train either almost daily or every other day, but with much lower per session volume. If you want to add strength with minimal mass (e.g. to stay in a weight class), this is the way. I think it doesn't get mentioned because most people can't train multiple times per day, five or six days a week, due to time, and also because most guys want to maximize mass gain.

You need to really know what you are doing to set up a program like that too.

The most natural thing a human can do is move their body through a plane of motion, we evolved to move basically, so it makes sense that working within the limits of your own bodyweight you should be able to train often and make progress fast.

When you start adding iron to the equation you should probably already be well trained, as well as having a solid schedule for how much to be lifting and how often.

https://www.t-nation.com/training/13064-pull-ups-in-5-months

Here's an older but good article.