Mini-14 folder
SKS Paratrooper Folder
if you want to get thru BA and want to spend under $500 (The SKS could be super nice for less than $500)
CETME
If you want something with a little more range and still want to spend less than $500
$500 to $1000 range I'd say look at Mini-14s and 16" AR clones if you wnat 5.56, and G3s if you like 7.62
If you want to step up over that price I'd say an AR in whatevever variant and caliber you think would fit you best. With those things the sky is the limit. I personally was really impressed with the one SL8 I got to fire, and also (I don't know where to even find these) he had a AUG that used M-16 mags. It would make a great SHTF gun.
M1A or FAL if you prefer 7.62 NATO and also if $$$ is no object.
Now that you have a price I's like to add this.
A battle rifle must be (to me):
high power enough to penetrate Level 2 BA
be accurate out to 350 yards
be quickly reloadable
have some provision for changing sights (Weaver mounts, etc.)
have a provision for attaching a flashlight
For under $300, and if 7.62mmx39 is acceptable ( for me its not), get an SKS. For $300 you got a SKS with a quality folding stock or Ram-Line or comparable sporting stock, a scope mount, a scope, a Lithium powered light and the hardware to mount it, and even a laser if you want it. All you got to do is learn to load with stripper clips. IMHO SKS detachable mags are much slower than stripper clips because they are so awkward, and are not worth the trouble.
IF you have to have detachable mags, you could find a paratrooper SKS that uses AK mags with a druganov stock for $300 if you were patient, but you'd have no $$ left for the little things I think are necessary.
Why do I not like SAIGA? I don't like AK safeties and in a battle rifle I like a pistol grip style stock. If you don't mind these shortcomings, I think it would be fine too.
. Thanks