When? Did it work?

It's getting a little ridiculous. I can't put my 4 month old down for an afternoon nap anywhere but the carseat, stroller, or my arms. He'll be drowsy or even basically asleep when I put him in his crib and he wakes up screaming 15 mins later. I've tried shortening and lengthening awake times, routines, etc. Thinking of starting nap bootcamp (ie, letting him cry it out for naps) this week.