Here are some tips that I tested: Make sure all your gear is featured or this season's gear. Use all Tier 5 if possible. Make sure you always end with an "A" Rating. After every Prime Engram Drop, switch to another character. Back and forth. I haven't done a lot of testing with this, but last night I was getting Primes every 8th run with this method.

lol

Yeah I love the grind but I thought about it today tbh, I'm like 446, so still a long way off weirdly - but I've played every day for a month, 10-12 hours per day, & it goes up to 550 in 2 weeks - & I've not touched any post campaign stuff, nor touched anything outside of solo ops on my 2 alts, so I've basically just levelled for the whole dlc outside of my first run thru campaign & that's not cool. It's also really really manipulative, the more you play (legit - no cheese) the longer your streaks between primes - I've gone days without a prime (record being 115 runs) & very rarely do I get more than 2 primes in a day. Anyone with any semblance of a life or who plays other games simply can't get near 450.

This, that is a problem, happened to me as well.

omg, that would be INFURIATING. I never understood the lack of bad luck protection.