Silver in chloride forms a crust of silver chloride, this crust will passivate the silver (keeping the acid from attacking it).
Silver will also form silver sulfate, so if you try to dissolve your silver in home made nitric acid (HNO3) using a nitrate (NaNO3) and sulfuric acid (H2SO4), you will form silver sulfate, which is not what you would want to deal with.
2NaNO3 + H2SO4 --> 2HNO3 + Na2SO4
Here the nitric acid (HNO3) will need to be separated from the sodium sulfate salts (Na2NO3), so if you wish to use homemade nitric acid on silver you must distill the nitric acid separating it from the sulfate salts.