At present, armament of Yury Dolgoruky-class nuclear-powered submarines (Project 955 Borei) consists of 16 three-stage solid-propellant SLBMs R-30 Bulava with flight range over 8,000 km equipped with six multiple independently-targetable reentry vehicles.
Lead sub of the project – SSBN Yury Dolgoruky – will be armed with 16 ballistic missiles, as well as two serial submarines SSBN Alexander Nevsky and SSBN Vladimir Monomakh. However, beginning from the fourth submarine SSBN Svyatitel Nikolai (Project 955A) the number of ballistic missiles will be increased up to 20.
This information was confirmed by Russian Navy Main HQ. "Indeed, the fourth and all next Borei-class submarines will carry twenty Bulava missiles with six MIRVs each", said the interviewee.