I have always wanted a Krag and recently acquired 2 rifles .  Being new I did not know what i was buying.  One is chambered in something around 24 cal.  The year 1918 is stamped on the receiver and the ser # is 19812.  It has a hole in front of the trigger guard.  The stock is short civilian looking and there is a screw that attaches the  stock at the front of the receiver.  What do I have?  The 2nd Krag is a US springfield model, it had a brass device added that prevented rounds from being loaded through the magazine.  This device was held in by a single screw through the side plate and is counter sunk  appears to be professionally installed.   Looking for help.

'JABGUTHRIE' - Welcome to the KCA Forum.

Your 1918 dated Krag, #19,812, sounds like it is a Norwegian model 1912 carbine in 6.5X55mm, (commonly called 6.5 Swedish Mauser).

These rifles were built at the Kongsberg Arsenal in Norway. (In 1918 the serial numbers ran to about #21,680). There should be a stylized Crown over the letter "K", on the receiver ring by the date.

Norway was under the control of Sweden until 1911, (note - I was mistaken. 'Parashooter' kindly informed me the Union was dissolved in 1905).
The countries shared the 6.5X55mm cartridge. Sweden adopted a Mauser arm, while Norway went with a rifle developed by Norwegian designers Krag and Jorgensen.

The Norwegian sling had one end that ended with a 'snap-hook'. The ring at the front of the trigger-guard was an attachment point for this 'hook'. There was also a ring mounted to the stock, behind the 'pistol-grip', to hook the sling onto.

The front sling-swivel was on the left side of a barrel-band, located about halfway up the 24" barrel. The stock forearm ran nearly to the muzzle.

A screw anchors the stock to the barrel several inches forward of the action.

Attached photo show an unaltered model 1912 "Karabin". Often these rifles will have a 'flat/checkered' bolt knob.