There are many good rifles in 243 Winchester. I assume you are talking about a bolt action rifle?
A lot depends upon your budget. But use caution due to the fact that there are a lot of inexpensive discount rifles being produced by most of the manufacturers including Remington and others to capture the low dollar market. In a good rifle you get what you pay for regarding the quality and craftsmanship of the rifle. I would suggest one of the following and also advise that some can be purchased at a local shop or gun show for a very reasonable price. The reason is a lot of guys buy a good rifle on a whim, sight them in and the gun never sees the field! Dealers usually do not allow that much for them on trade in so they sometimes will make you a great deal on them so they do not have them setting on their shelf for months and months tying up dollars! I would look at some of the following rifles in 243 Win. Remington Model 700, Winchester Model 70, Savage Model 10 or 110, followed by Howa, Mossberg and Browning for examples. But stay away from the bargain basement priced rifles. They are not of the best quality both in parts and manufacture. For example of a good deal! I purchased a Remington Model 700 with scope in 243 Win cal. in excellent condition a couple of years ago at a gun show for $450.00 which included a decent scope and mounts!
Be sure to check the bore and also look at the locking lugs on the bolt. If they have very little or none of the finish worn off on the lugs you probably have one of the rifles mentioned above that spent 98% + of its existence on a safe or gun rack!
Individuals with guns are citizens! Individuals without guns are subjects. *John Adams
The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!