One other option if you have not tried it is to use different manufacturers and bullet weight. I must say that for a hunting rifle the 1.5 is not all that bad. However a suggestion would be to try the following two rounds in it.
1. Federal Gold Medal Match 168 Grain
They are loaded with Sierra Match King 168 Grain Bot Tail Hollow Points
are used by a large majority of the LE SWAT Sniper Units through out the
USA and others.
2. Remington Premier Accu-Tip 165 Grain
I use the Federal in my 40X Sniper Rifle in 308. And the Remington Accu-Tip in my Remington 700 CDL which is chambered for 7 MM Rem. Mag.
I have achieved under .447 five shot groups in both rifles using the above rounds from the bench.
So if you have not done some testing regarding achieving you desired results before going to the expense of another rifle or getting yours rebarreled. Of course that is one trmendous excuse to have to get another rifle!!!!