Enough talk about top bench rifles! What are the rules you're shooting under? Is it for any rifles, or are there sporter limitations? Can you use a 3" wide forend? Is weight limited? Is scope power limited? You need to know the rules before running off and buying something that either won't be allowed, or won't be competitive.
Shooting light rifles off poor rests is much more difficult to do well than using Unlimited benchrest rifles. Shifting from one bull to another, holding the rifle very consistently form shot to shot is detrimental to good scores. Technique is extremely important because the rifle starts moving in recoil before the 22LR round leaves the muzzle.
When shooting light rifles, I've found it's important to maintain about 4 pounds of pressure against the shoulder. Rifle position should be consistent and position of the rear bag should remain constant from row to row. That requires vertical adjustments on the front rest, but horizontal adjustments are a big plus as well.
I've been shooting Rimfire Benchrest for a fair number of years and run both IR50/50 and Plinker competitions at our club. Last year, I had the match of my life, shooting 74 consecutive 10s and Xs, getting a 9 on the last shot of the tree targets (250, 250, 249). My rifle is a custom Rem 40X, bought used for $1,600, and shooting very high-priced match ammo.
If anyone wants a good match rifle, Benchrestcentral.com Classifieds is the place to look!