If you can't do it with the rest you have a high dollar rest isn't going to help you. You have a great rest for what you are doing, guys use them in benchrest comps and do good. Bipods don't do great off a bench, if using a bipod shoot prone.
Work on your form and consistency. You may need to tweak your load, seating depth,charge weight.
Then it may be your barrel doesn't like the bullet you are working with, it happens all the time. And after you have made sure you have done everything to help the rifle shoot accurately, ie; float barrel, bed action. And is the rifle you have caplable of shooting 1/4 moa?
Guys that can shoot can take a capable rifle and load and shoot 1/4 moa and less off homemade sand bags, if the rifle and load is capable it doesn't take a high dollar rest. I would recommend having someone shoot it that you know is an accomplished shooter. Someone that you know consistently shoots small groups, and see what it does with him, before you go spend a bunch of money on a rest. I shoot F-class both long and mid range and use a JJ Lo and a SEB Joy Pod and still a lot of times I go to the range to do load development for rifles other that my F Class rifles, I will take a Sinclair rest, quit similar to yours and it works just fine. I have shot many groups in the .2's and .3's and some in the .1's with it.
I would figure out the problem you have first, be it wrong Bullet for your barrel, wrong seating depth,your shooting form, is the rifle capable of that accuracy, before adding another factor and spending money on a rest when it may be best spent on fixing the gun.
But buy all means keep moving forward and do try F-class as soon as you get a chance, it will humble you and then you will start learning what you might be doing wrong, and the people are great and most will help you. I would invest in a gun for F-class before I spent big money on a rest, you could get buy with your rest just fine as you are learn the ropes.
Good luck and have fun
