+1 to what cayugad says.

I wouldn't mess with the rifle at all, write down the load - exactly, so you can come back in future years and know what works well.

However, you can still tinker around with other loads as long as you don't make alterations to the gun itself. That's one thing to do. Like working up a long range or short range load, or a varmit load.

Another thing would be to buy a different rifle (different style maybe? - i.e. traditional vs. inline) and have fun with that one.

I wish I had your problem!