K31 proven loads

[k31]

Hi
Re: K31
Anybody help me please. I can chamber the 7.5x55 case and PPU Privi 174 FMJBT at 80.034mm and the boat tail is almost at the end of the neck. There are no gouges on the bullet jacket. The bullet does not fit into the magazine. I have read that 2 other people have set their similar bullets at 77 and 77.2 mm OAL. That is 2.835 mm under my length, which relates to a jump of 71.9 thou.
Am I missing something here. I was looking for about 25 thou jump??????
Confused of Norfolk.

[k31]

Further to my last thread. I have black marked the bullet and at 79.22mm it fits the magazine and the rifle with no witness marks. The base of the bullet is at the base of the neck, just where it turns out.

Has anyone got any info for me or any ideas, especially if they have loaded with the Privi PPU 174 gn Jacketed.

[lapua338]

I trim the case to 2.181" and the cartridge OAL with the PPU 174gr FMJ-BT is 2.972".

Never experienced a problem with cartridges not fitting the magazine.

[k31]

Thanks Lapua for your reply. Are your 174s marked .30. These particular bullets seem to have a very long pointed nose, not far off the original GP11 bullet shape and a small bearing surface set well back.

I was experimenting with the bullet fit to see where it would fit the chamber and cycle properly and smoothly. That appears to be 3.123"
This will also fit the magazine.

You suggest 2.972" which is 0.151" smaller. This will put the base of the bullet right inside the main cartridge chamber, beyond the neck. Is this acceptable? I was told that the base should only come to the base of the neck. Was I misinformed?

I have a feeling I have a worn out throat in the rifle, which is a disaster. Can anyone suggest a bullet with a fatter design to fit the bill and obviate the wear. sign85 sign01

[k31]

I have made a lead round which is OAL 2.852 and cycles nicely, backed off 25 thou from the "lands". Not exactly what I wanted from the rifle but needs must.................until I find a more useful jacketed bullet.

[dromia]

I think that you are getting rather hung up on the jump distance to lands, you rifles throat is what it is just work with it. Worn out throats in military rifles are not necessarily a disaster.

Have you tried any of you condom loads yet with the bullet seated to the oal for the cartridge, at the end of the day it is target that will tell you what you need to know about your loads and rifle.

Seating below the shoulder isn't a problem per se however it does reduce the case capacity and you powder weight may have to be adjusted accordingly.

Have you slugged the bore of your rifle so as to be able to select an appropriate bullet, with cast diameter to fill the throat is far more important than seating out to the lands which you do seem to have fixation about.

[k31]

ok Dromia, I realise I have fixated on the jump to lands. Now I know what I have to do, I will get on with it. Condom loads, as you put it, will be tested forthwith. sign92

I have also prepared a lead round for the rifle with appropriate diameter and will test it out.

As for jacketed, I will have to look around for a bullet which will better fill the throat. I know it isn't the end of the world but it is disappointing. sign01

Especially as many articles on the forums and elsewhere indicate these rifles were hardly ever fired. I seem to have purchased the only one from which they fired thousands of rounds. :lol:

[Mezzer]

K31

Suggest you take yourself over to the Swiss Rifles Forum and have a look through the reloading section. These guys live and breath K31's and all that goes with them. Use the search function before posting on the Swiss Rifle forum and I'm pretty sure you'll find the answers you need.

Mezzer

[k31]

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.

[DW58]

There are lots of different bullets you could try, many manufacturers make 175gr projectiles, you don't have to stick to PPU.