Im getting stuff together for my 338 lapua build.... my action has a seekins cut for longer 300 gr bullets..... I went to buy the seekins DBM and mag and got hit with the news that they are backordered and havemt got any in THIS YEAR YET!!!!! I need the length in the mag... seekins is suppose to get me 3.9+ of clearance..... any other options out there anyone knows of thats a quality product?