Some opitions to consider for a Dm rifle.
a mosin in good shape with a scope, would be more than adequate for a dm rifle. a big bonus is ammo is cheap and many preppers have a mosin so ammo is available.
You could also put a scope of a ar 15 and have a pretty good dm rifle. especially with the 30 round mag. With a 1/7 twist you can utilize heaver bullets to max out of the range of the rifle.
with the Mosins you have to make sure you have a good scope mounting system... all the bolt on kits that attach to the rear iron sight etc are all worthless. you must have it properly tapped on the action and then you must have a curved bolt handle installed to achieve the propper eye relief for the scope. Ammo is another deal where you may have to load your own to get a load with a decent bullet in it. but thats no biggy for a person who already reloads.