You also have to be able to run, hide, have excellent field craft skills, and be in awesome shape.
Know why it was so hard to catch Horning?
He was 33 years old, not 53, had excellent field craft skills, had already extensively hiked and camped the terrain, and he was in the physical condition of a marathon athlete. Horning was in awesome shape. He could just start running and keep running, full tilt, even in that terrain.
A silencer is a plus, it does NOT make you invincible. One of the reasons chases go on for so long is that it's fat, pudgy cops doing it, and they are trying to catch the perp alive. In a prolonged chaos situation, that will change.
EVEN though you are getting old (and yes you are, amigo), IF you had the field craft skills, IF you were in marathon shape, and IF you had the precision rifle marksman abilities needed, yeah, you might be one deadly mf with a suppressed rifle, especially if you had a different weapon, or even the same weapon with a few extra inches on that barrel.
But that is evidently not the case here. What we have is an aging man with no prolonged experience living in the woods and a cobbled together toy.
The rifle doesn't make the man, it's the man that makes the rifle.