Solitary...I would think the 85 gr HPBT would do fine in that Ruger compact...If I remember right they have a 16 1/2 inch barrel...so you won't be pushing it as fast as my Ruger (rebarreled to 24 inches)...I would guess you could hit about 2700 fps...I have killed several out there at 250-300...So if his range would be around 100 yards...the velocity at point of impact should be roughly the same...They do mushroom well at that range...At a lower velocity they will upset less and retain their weight better...I was also concerned about hitting bones at close range and have killed several inside of 50 yards, hitting some in the lungs and some through both shoulder blades...didn't have a problem recovering any of these...These are not your typical hollow points...most people hear hollow point and think they "blow up" on impact...In skinning the deer killed with this bullet I have noticed that it actually penetrates a couple of inches before it opens up, and then penetration depends upon impact velocity and the amount of bones it hits...It has always penetrated through the body cavity and at that point you are just messing up meat on the other side...As I stated, it gives an exit hole with center lung shots and on high shoulder shots it penetrates both shoulder blades...

Actually a worst case senereo is the speeds that Roskoe is pushing the bullet...as you know the faster you push a bullet, the faster it will open up...I've noticed exactly the same thing Roscoe mentioned...On lung shots, deer hit with Partitons run farther than deer hit with the "softer" bullets like the Sierra 100gr SPBT...The Partitions give a exit wound, but its not as big in diameter as the 85gr HPBT...I tend to like a bullet that will give a good exit wound on center lung shot deer, but not on high shoulder (bullet through both shoulder blades) shot deer...If the bullet is hard enough to always exit on high shoulder shots, then that deer will run 100-125 yards with a center lung shot...In some areas that is OK...in the swamps and cutovers in eastern NC I don't want that...

I'd be curious to know how fast you can push it with the Ruger Compact...
Let us know how things go with your son....Best of Luck