With the latest Chapter Approved and Munitorum Field Manual coming out there are images of what's inside being shown in various places online. I grabbed a few of them and its time to share.
via Bolter and Chainsword
http://www.bolterandchainsword.com/topic/370380-chapter-approved-munitorum-field-manual-2021-mk-ii-gt21/page-10
http://www.bolterandchainsword.com/topic/370380-chapter-approved-munitorum-field-manual-2021-mk-ii-gt21/page-10