Laravel: Unable to set `setTable` to eloquent model from controller

I am working in laravel 5.4 (stock management system) and have dynamic table means table generate on create new store. Each store have its own stock table with his id like store_8_stock. I create StoreStock model and when set table from controller its not working correctly:

$storeId = $item['store_id'];
unset($item['barcode']);
TransferList::create($item);
$insertStock = new StoreStock;
$insertStock->setTable('store_'.$storeId.'_stock');
$stock = $insertStock->where('item_id',$item['item_id'])->first();
if($stock != null){
    $stock->qty = $stock->qty + $item['qty'];
    $stock->save();
}else{
    unset($item['item_name']);
    unset($item['store_id']);
    $insertStock->create($item);
}

for $stock = $insertStock->where('item_id',$item['item_id'])->first(); its working fine but when its coming on $insertStock->create($item); its showing error store_stocks table or view not found

$item Contains

array:11 [▼
  "barcode" => "8901023007446"
  "item_id" => 2
  "item_name" => "My new item"
  "mrp" => 12.0
  "sale_price" => 60.0
  "purchase_price" => 50.0
  "qty" => "2"
  "free_item_name" => ""
  "product_vat" => 0.0
  "vat_status" => 0
  "store_id" => "8"
]

can any one please tell me what is wrong in my code?

via Chebli Mohamed