Originally posted by barnbwt
*The K31 in combination with GP11 ammo of the day is ludicrously accurate for an iron-sighted standard rifle. I don't know how comparable the Swede's 8mm was to GP11, but unless it was even better than their excellent Mausers, those vaunted tack drivers probably weren't as accurate as the Swiss guns in practice. Even today with match ammo it's nearly a wash.
I don't think the 8mm Swedish M40 rifle has ever been particularly renowned for it's accuracy. The rifles were just German made Kar. 98k's rebarreled to the Bofors 8x63mm machine gun round. It was never very widely issued, being mainly used by heavy machine gun troops in fortified positions in order to maintain ammunition commonality.
You may have the 8x63mm confused with the 6.5x55 used in the Model 94 and 38 carbines, plus the Model 96 and 41 rifles, all based on the 1894 small ring Mauser action.
These were all very well made weapons, some of the earlier ones were actually made in Germany since at the time Sweden didn't have the capacity to produce them fast enough. It was however, stipulated in the production contracts that only Swedish steel could be used to make Swedish rifles.
All of the Swedish 6.5 bolt guns were very well built with closer tolerances than was the norm for military rifles of the time. That, combined with the light recoil and good intrinsic accuracy of the 6.5x55 round, made them excellent shooters both then and now.
I'd imagine the M40 rifles were probably high quality rifles as well and I imagine that any cartridge designed by Bofors was probably pretty accurate. Despite all that, the M40 wasn't known for being particularly precise because it definitely lacked one quality that really helps accuracy, low recoil.
The 8x63 was the same length as our 30-06, but the case was larger in diameter and held about 15 percent more powder.
The 30-06 M2 ball cartridge used in WWII had about 2500 foot pounds of muzzle energy, the 8x63 had over 3000.
Not a lot of fun in a turn bolt rifle with a steel butt plate that only weighed about 5 ounces more than the 6.5x55 M96!