Depends on the rifle. As long as the barrel is tight to the receiver, not a problem- it is the stock that is loose. Try tightening mounting screws with a GOOD screwdriver (to keep from bugering up the heads of the screws). You may have a stripped thread on a screw, or may need to add a shim between stock and barrel- try cutting strips out of a business card, and use them. If the gap is wider than that, you need to see a gunsmith.
I have no mention of Kreige in my references as a gun manufacturer. Kreiger is a barrel maker. Please repost with a full description of your rifle, all markings, and we will do ou best to get you an answer.
What lenght? Also It will be, at best, a slight improvement over the stock barrel.
Best left to a gun smith.
Best left to a gunsmith
Best left to a gunsmith.
Best left to a Mauser trained gunsmith
Best to ask a gunsmith for assistance.
Best left to a gunsmith.
Best left to a qualified gun smith.
If there is no maker's name on the rifle, it is likely a (former) military rifle. Without a full description of the rifle, and ALL markings on the rifle, there is no way that we can answer your question. Your best bet would be to take to rifle to a local gun dealer. Sorry-
Any of the major brands will do a good job. The best system is Outer's Foul Out.
Best source would be old gun catalogs and magazines.