Results after a little testing: 8 out of 10 times when one jammed, BOTH did. I shouldn't have to tell you how astronomically low a probability that is. These should be independent events, so both of them jamming at the same time is a 1% probability (since the WHK has jam chance reduction). Having it happen almost every single time has got to be a bug.
EDIT:
I ran some additional tests and I believe it's an issue with the jam chance reduction quirk. I spent 600 rounds on a Dire Wolf with 2 UAC10s and got ZERO double jams, which is actually lower than expected. I then did a CTF-3D with the 30% jam reduction (for UAC 5s) and got 6 out of 12 times they jammed, they both jammed. I then loaded up a WHK again with the TC removed and 720 rounds, which after 63 double taps had FIVE double jams and ZERO single jams. I reran this test and got 2 single jams and 6 double jams. So to recap the data:
Dire Wolf (no jam reduction quirk): 600 rounds spent, ZERO double jams.
CTF-3D (30% jam reduction quirk): 300 rounds spent, 6 out of 12 times they jammed, both did.
WHK (30% jam reduction quirk): 1440 rounds spent, 2 single jams, 11 double jams.
I think this data shows it's pretty obvious that the jam reduction quirk is making both jam if one does, as the WHK was roughly 120 double taps. That follows just fine with a 10% chance.
There is an Enforcer and a Jagermech variant that can both mount more than 2 (and have the jam reduction quirk), I'd bet this would be extremely apparent on them. Unfortunately I do not own these 'mechs.
Edited by Zoid, 20 April 2016 - 06:44 AM.