I don't feel comfortable "recommending" load data for rifles of which I have no personal knowledge, therefore, this is my disclaimer prior to
posting my own load data. Particularly if you are a reloading novice, this is important. Your k31 is not a new rifle. These powders/projectiles are! Not
knowing the particulars of your rifle, I can only say how these loads performed in MY OWN RIFLES! They may not perform the same in yours. I can say
that these loads performed slightly differently in each of the three k31s concerned. This would be because not all barrels are absolutely identical. You
MUST approach these loads with caution, approaching them in .5g increments. We all love these old SRs, but no one knows what stresses your action
may have sustained before you got it, therefore accept the fact that the loads I'll be posting worked for me. They may or may not work for you. You
experienced reloaders know exactly what all this means. Consider your own rifle and be safe! Regards

     All rounds were fired from an "Accurite" shooting device that accepts the entire weapon, allows natural recoil and "contained muzzle jump". Micrometer
windage/elevation & "cant" adjustments are used. All shots were 5rd groups from 100yds. Consider temperatures were variable, which may have an
effect on your rifle's performance. No extremes, however.

      Three k31s were used and categorized by their mfg date. Extensive reloading narrowed the projectiles down to two, which worked the best in THESE
three rifles. The 165g is a remington .30cal PSPCL. A jacketed soft nosed projectile with flat sidewalls and flat base. The second projectile is a 173g
U.S. Military issue "pulled" fmjspbt. I reiterate, the following loads performed well in THESE THREE RIFLES. You must approach these loads
responsibly based on YOUR knowledge of YOUR rifle.

      All three k31s are pristine samples of their genera.

      k31 #1 mfg'd 1937

     165g
      N203......40.5g.........1.69"
      BLC2......39g...........1.75"
      3031......36g...........1.8"
      414.......43g...........1.56"
      4064......37g...........1.0"
      4831......47g...........1.13

      173g
      414.......43g...........1.10
      4064......39.............97"
      BLC2......40g............1.59
      4350......38.5g..........1.76
      3031......35.............1.97

      k31#2 mfg date 1946

      165g
      3031......36.2g...........1.85"
      4064......37g.............1.0"
      414.......43.1g...........1.65"
      4831......47g.............1.23"

      173g
      414.......43..............1.15"
      BLC2......40g.............1.83"
      4064......39..............0.91"
      4350......38.1g...........1.94"
      3031......35..............1.75

      k31#3 mfg date 1955

     165g
      N203......40g..............1.98"
      3031......36g..............1.87
      BLC2......39.1g............1.40"
      2520......39...............1.55"
      4831......47g..............1.30"
      414.......42...............1.57
      4064......37g..............1.0"

      173g
      4350......38...............1.99"
      3031......35g..............1.85
      4064......39g..............0.88"
      BLC2......40g..............1.65"
      414.......43g..............1.10"

FURTHER TESTING

All rounds fired from an Accurite Rest, all groups consist of two five rd groups.
Brass, Norma, Projectile- 165g Remington SPLSC & 173g fmjbt,  "pulled". Primers, CCI-LR. Brass TTL & champfered inside/outside.

      165g
      4831SC........45g........1.65"
      IMR3031.......35g........1.30"
      IMR3031.......36g......... .70"

      173g fmjbt
      4831SC........48g......... .88"
      IMR3031.......34g......... .90" in a perfect vertical string.
      IMR3031.......35g......... .44" & 1 flyer .82" out
      (second group 3031)....... .71 & 1 flyer .75" out
      All BLC2 loads exceeded 2"

      The above loads were the result of EXTREME CARE of each barrel after each group.( brass cleaning etc) Your rifle may or may not show similar taste
 for these loads, and there are certainly a myriad of other loads that may prove better performers in YOUR rifle. Reload Safely! And good luck!!

      I never recommend bullet depth seating as it varies slightly from rifle to rifle, (and a projectile jammed tight against the lands/grooves CAN make differences in chamber pressures, although usually not dangerously. This will definitely affect projectile performance.) Partially seat a projectile in an EMPTY UNPRIMED cartridge and ease the bolt forward to full lock. Eject the whole works, measure it with a micrometer and back it off another .019 to .021 or whatever your particular reloading book recommends. The "lyman casting handbook" is a good source of odd reloading info! No, I did not i/o true the case mouths. I developed these loads based on the recommended TTL and used materials & methods allowing me to shoot often without hours of technical fooling around with components. One thing I should have included is the primers were CCI. Sometimes you hear that magnum primers work better with some powders that have burn rates that somehow don't perform as well as you'd expect. This happens to be true, but you need to do those experiments with care.  Be careful.

      Pierre