It would help to know what kind of rifle he has. Perhaps the rifle he has is not suited to roundball. Some other considerations are the weight of the rifle, the caliber, and the kind of stock on the gun. All of these will effect the recoil.

Also the type of shooting situation he is facing as to distance and kind of setting will all make a difference in the kind of projectile he might want to shoot.

As to whether roundball would help. Yes, roundball with a lower powder charge often times will have reduced recoil. If you keep the powder charge around 70 grains the recoil is very mild if any in the right rifle, and you still have plenty of power to take a deer out to 75 yards.

Some other considerations would be a ball-et. They come in 275 grain, are easy to load because they do not require a patch, and with 70 grains of powder are accurate and deadly. Buffalo Bullet company makes a number of sizes in ballets. A old rule of thumb is faster the twist, longer the projectile. So if this is out of an inline with 1:28 twist, then get the 275 grains ball-et. If it is 1:48 or slower, then you might want to look into I believe the 245 grain ball-et.

Hope you can find a load for your father to use......