My Savage works well with these. It has a loose bore also.
Try the blacks with .458 bullets
Try the reds with .450-.452 bullets.
Good luck, Zen
http://www.midsouthshooterssupply.com/item.asp?sku=00072H15045BR
http://www.midsouthshooterssupply.com/item.asp?sku=00072H25045SRR