Just for future notice, I already have an Ar-15, a .22 LR, a G17, and a Mossberg 500 (and of course, the mosin 91/30). Also, how good do you guys think an Ishapore 2A1 would be in .308 for this type of situation.
What you have, depending on how you set up the AR and Mossberg, should be good.
You said hunting, defense, and handle some abuse... for under $400. That last part is your hardest requirement.
The problem is that those requirements also lend themselves to much different rifles. Hunting... what are you wanting to kill? Small game, like rabbits or squirrels, would be fine with a .22. Deer, you can take with a 5.56mm... but it is kind of under powered for the task. Personally, I'd opt for a .30-30 or larger for that.
Defense, ARs are the way to go. If your jurisdiction allows it, five 30 round magazines would be enough to get you away from most threats. It isn't going to be a Rambo style war, and if you meet a sizable threat, you are likely going to die duking it out with them. If you don't feel comfortable with 30 rounds, toss a Magpul 60 round drum in your gun to start, and deal with the weight.
The AR has flexibility with upper conversions... but that is a lot of weight with uppers, magazines, and ammo. Even just an AR... with a basic load out, is going to be more weight if you are carrying what you need to survive.
I have a Ishapore 2A1... and it is a great gun. It is a No 1, Mk III... in .308, with a 12 round magazine (not something you are going to get extra magazines and swap it). Very easy to clean.
But the bad is that it is a No 1, Mk III. They were used for some time in India, along side the FAL, but bolt actions aren't really the best for military situations. They are heavy, and even if you have stripper clips, the load out weight is going to be a bit much. Not to mention... it is a long gun (few inches shorter than a 91/30).
I really don't recommend rifles for these threads, being I think the chances of it going down the way most people think it will are remote... and also, I have most of the guns mentioned so far. No need for me to decide... because if I need something, I'll just pull it out of the safe.
A Garand works, but if you don't have an adjustable gas plug, you are stuck with M2 ammo. Most commercial.30-06 will bend the op-rod (shooting an amount of them... one or two rounds would be an issue). But if you maintain the gun, and watch what loads into it, it will last for a while. Over your price range... even at CMP (best source of them).
An SKS is a good choice, but it is usually a ten round gun... or modified for more capacity. With the latter, make sure it functions. Just over your price range, as they dried up fast.
Mentioned the AR, but an AK is just a cheaper cousin. Very good rifle, just doesn't have the convertibility of the AR. Even in AWB states, you still see people shooting compliant models... so, they span the country like an AR. You can find WASRs in the price range to a hair over... but most others go above.
The M1A is nice rifle. Gives you .308 power, with repeatability of a semi auto. Mounting a scope is a pain/costly. Not to mention, M1As are expensive. You can find deals... but deals with them are a early 1990s NM rifle (built off USGI parts), for $1,700... which had less than 50 rounds through it.
A .30-30 or comparable lever action would be a good choice, and give you the ability to fire a round or two further away (LeverEvolution ammo, and figure out what it does ballistically) if you need to get out of the area. Can find one under the price range... if you look used.
A budget hunt rifle works, and can be found at most hunting stores. If you wait for it, you usually can get one during a sale for dirt cheap. Accuracy is dependent on the gun/ammo, but usually can get an ok scope (they usually don't have iron sights) and do minute of deer out to 200 yards. Probably can do one with scope at or slightly above your price range. These are the only ones I don't own, being I have rifles that can fill the void.
While it was out of your range, I did find a nice Remington Model 7 that my FFL picked up used. Yanked the Leupold 2-7x off and added a Leupold 4.5-14x. You find decent rifles at gun shops... usually lightly used hunting rifles that were sold off because the owner got something better, didn't hunt with it and got rid of it, or died and the spouse/kids didn't want it.
I'd say, buy a gun you want... not one preparing for a situation that might not come. If you want an SKS... put money away until you can buy a good one. If you want a M1A, save up for a little bit longer, and get one. Ishapore rifles can be found at about your price range... but why get a bolt action .308 that was made in the 1960s if you don't want it? I really don't recommend compromising in this situation.