K31 proven loads

[mag41uk]

FWIW I reload for my K11 which has a more generous throat than the K31.
Mine was well used when I got it (dates to 1919) and I have put at least 4k down it since.
As I rarely use the mag, a few comps each year, the COL is of little significance.
My COL is longer than factory spec and I have never worried about where the base of the bullet sits.
I have used PPU 174gn,Lapua 155 and 167,Sierra 155, 168 and 190gn smk`s.
TBH I haven't seen a great deal of difference between them but must say the 155 scenars work particularly well.
It had an outing at 900 yards yesterday and I can keep them on the screen with about 3/4 in the black.
At 600 yards any of these bullets will stay in the black in still wind.
The PPU 174gn 308 bullet is made specifically for Swiss rifles as it duplicates the original.
As an aside the bullet shape was used a model for the US 30-06 service round.
Offhand I think the Sierra 168 is fatter in the ogive than the PPU.
When I get chance I will compare the PPU with some 155,168 and 175 smks.
I have never bothered to check for distance to lands in my rifle.
But as said by Adam and others don't worry about it, load them and shoot them and see how they group.
I use N150 in mine.
Tony

[k31]

Cheers DW58. :goodjob: It is only because I am new to this K31 game that I get a bit worried about things. Once I have been doing it a while, then maybe my worries will go away.
Hi Tony, great message. Thanks a lot. sign92 I will have to compare some bullets. I'll check out the 168s SMK as you said they were fatter. Meanwhile, I will persevere with the PPUs and hang the jump!!! wtfwtf sign92 :flag5:

[Mezzer]

Already been on the site, Mezzer. I am a member there. All I was doing was exchanging views on this site, to see if I could glean any info from sources who use the PPU 174 gn bullet.

Good stuff!

In which case you will already know that Col and bullet seating depth for a K31 IS a big deal.

Resize a case and open the case mouth up a little. Insert a projectile and carefully load the round by pushing the bolt slowly forward into battery. Remove same complete with the bolt. Look for the first sign of contact marks on the projectile and take this measurement. Do this a couple of times more with fresh projectiles then take the average of the measurements. Subtract 1 mm from this measure and that is your CoL for your rifle. Blacken the bullets with a marker to make the witness marks more obvious if you need to.

Mezzer

[dromia]

His problem is when he does this in his rifle the bullet is that far out he has hardly any bullet retention and it is over long for the magazine.

[k31]

I have made some jacketed and will shoot them Thursday. Then I will know if I have a problem. Hopefully not!

[k31]

I have tested a 174 gn PPU round pushed into the breech and withdrawn it with the bolt, as you said. The bullet was held firm all the time and OAL measured at 3.173 inches. This was a new cartridge case and a new 174 PPU bullet jammed into it. I pulled on the bullet to see if it would move and it was firm, so it could not have been pulled out during the unlocking cycle.
The bullet was almost fully in and it's base was at the neck of the cartridge case where it turns out. It didn't quite fit into the magazine by 0.050 thou.
I have reduced the OAL by 0.050 thou. This makes the OAL 3.123 inches, which fits the magazine.
This OAL length is 64.9 thou larger than the original GP11. Amazing or what!!!! Have I got a Friday afternoon rifle.

[Whizzbang]

Have I got a Friday afternoon rifle.

No such thing; it's Swiss.

[k31]

It was a tongue in cheek remark. The main gist of the message, seems to have been missed. I was trying throw a new light on OAL and bullet fit, which hasn't been addressed in this thread. The original cartridge GP11 was set to 77.7 mm a full 1.6 mm smaller than the cartridge I tried out. My hidden question was does anyone know why. If my rifle has negligent wear at the lands then the stand off distance the Swiss used was 2.89 mm from the lands. If there is wear in the rifle, which I suspect is the case, then this stand off will be smaller. What I would like to know is exactly what the Swiss tried and tested for their round. I can then determine the wear on my rifle. I have been told that the PPU 174 gn replicates the original bullet. I am only interested in the technical point. My rifle will shoot how it does and I will live with it. This is another way of subtly gauging the rifle.

[k31]

Hi, at last I have tested my rounds out today in 4 groups of 3 rounds per group at 40 yds. Using iron sights only. 43, 44, 45 and 46 gns charges of Elcho 17. PPU 174 gn set to 77.7mm OAL. The 46gns Elcho17 proved the best load. The Privi cases full sized and a light factory crimp, I got 3 to cloverleaf, 1/2" and 1/2" groups and a 1" group but that was me getting used to the rifle. This load chronographed at 2355, 2351, 2357 fps.
Will go on slowly up to factory spec. velocity to see if I can get consistently tight groups and then, where the groups start to open work back to a consistently good grouping charge.

[jsangel]

Hello all,
I have a K31 from 1950.
So far i have only put Privi ready-made through it, i now have dies, Privi 174gr bullet heads and a kilo of Vhit N140.
Do you have any recommendations as too loads?
In the future i would like to shoot cast bullets through it also, any ideas with regards to which mould and powder would be appropriate?

Thanks, Jon.