[ddd oo7]

Ammo is a major part of your problem. 147 ball ammo won't shoot well in any rifle because it is not precision ammo. It is made for machine guns.

If you want to get a baseline of what the rifle will do then get some 175gr Federal gold medal match. I assume the rifle was used when you got it...so Clean the barrel thoroughly with wipeout patchout and accelerator paying special attention to the Carbon ring at the front of the chamber. Then shoot 20 rounds of the Federal Gold Medal Match to season the barrel to the Sierra bullets. Then shoot 20 more in 5 shot groups to see how they do.

Use a bag in the rear to support the stock.

Use a piece of paper to make sure the barrel is floating.

Check to make sure all scope ring and base screws are tight...but don't overtigten if you don't have a torque wrench.

 

[ddd oo7]

Reloading is the way to go. It will save you some money. More importantly it will allow for more precise rounds.

However precision shooting is expensive any way you cut it.

 

[ddd oo7]

Depending on the scope...cranking the magnification up changes the eye relief. This is true with the vast majority of low to mid range scopes and even some high end scopes.