Unless you have an exmilitary rifle or are involved in certain types of target shooting, the chances of you haveing a worn out barrel are pretty slim. The average hunting rifle, includeing most of the standard length magnums will get several thousand rounds through them before accuracy degrades to any noticeable degree.
Now, that being said and not what you asked for, there are a couple of things you can look for without pics.
First take a look from the breach end of the rifle at the bore, there are a couple of things to look for rhat are easy to see,
1- Is the throat (where the rifleing lands start) worn down. It may still be shiney and bright but worn. There shoul also be a bit of a ramp on each land, this is normal from the chambering reamer.
2- Is there any frosting or light pitting in the bore. Sometimes pitting doesn't effect accuracy, but will usually effect pressures after extended shooting without cleaning.
3- Check the muzzle, are the lands sharp or worn smooth, either from shooting or an improperly used pull through cleaner. Usually pretty easy to spot.
4- While your there, check the edges of the bore for burrs and look down the bore for large pits or rust.
Some of the older enfields have metford style rifleing which has rounded rifleing to stop erosion from cordite powders and rifles meant for black powder or lead only will sometimes have different looking rifleing than more modern rifles.
It isn't unusal for older rifles to have bores with lines running in tangent to the rifleing from chamber to muzzle, these were manufactureing inclusions, not intentional but considered acceptable, especially on wartime production rifles.
That's just a very brief beginning but will cover most of what you need to look for. bearhunter
