I have a model 983 22WMR, so I can help a little.
The bolt handle is the only locking lug.
The firing pin is offset in the bolt for rimfire, so either you would have to convert it to centerfire somehow or a new bolt.
5.7x28 will not fit in a std WMR magazine.
Really, other than the use against Kevlar, I would think that the 22WMR or the 17HMR would be a better round.
I would like to know the SAAMI or CIP rating for the 5.7 is. One reference said that the case was able to stand 50,000psi.