7.5x55 Swiss, help a brother out

[Jeff Michel]

NOE just made a run of the K31 bullet moulds. Currently he has 2, 4, and 5 cavity available. All gas check.

I believe that NOE made a custom mould just for the 7.5 swiss. It was designed to work in that super short throat. You might google 7.5 swiss and see if you can locate the Group buy on that one, I think I have one of those moulds but I am not sure. I am sure someone here would be happy to cast you some to try in your Swiss if you asked them too.

[JSH]

As to dies. I tried everything I was told would work for the k31. I spent more in dies in 18 months than I did on two of these 89.95 rifles.
I finally gave up and tried what I was told would not work. 30-284 wildcat dies from lee. It solved all of the problems I was having. It does not size but very little of the case body. Makes for perfect feeding and bolt lock up. Try shooting a 40 round match and having to smack the bolt on everyone to get it to lock up in order to fire. Stone bruise on the heel of the hand for a week.
Jeff

[madsenshooter]

The collet neck sizing dies I got from Lee were marked 30-284. Can't remember if I got them direct from Lee or from Grafs.

[madsenshooter]

Now I remember, I ordered the die parts off the Lee site, already had the correct length die body. I ordered 7.5x55 but received parts marked 30-284, same-o, I know. Goody, 164.2gr checked and lubed, and you're getting them sized .311. .312 won't start into the neck of a fired case. My chamber might be a tad tighter to go along with the extra tight barrel. But if the neck on yours would happen to be the same as mine, .312 would cause chambering problems. I'd rather not be the source of a problem. .311 goes in with my fingers and creates a partial vacuum in the case when it's quickly pulled out. Pop! Hope you find some time to play with the other bullets you found while waiting for these.

Took my rifle apart, the tight barrel was made by SIG. Most K31 barrels were made by Hammerli.

[Rich/WIS]

The CMP Forum has a thread going on reloading for the K31, Redding Dies are specifically made for the larger K31 chamber and do not oversize the brass

[madsenshooter]

Got some boolits done for the OP, all packed and ready to ship Monday. Had a little time on my hands today and decided I'd shoot a couple 100yd groups so he could see how they perform in my K31. Load was 25.7gr SPP210, which burns around 4198 speed. Previously clocked at 2000fps. First group was the 5 shot group, I'd had the rifle out of the stock and expected a little unpredictability, by the second group it was settling in again, and I was having fun!

[Kraschenbirn]

Took my K-31 to the range last Sunday and fired fifty rounds off the bench (no sandbags) just to keep my hand in. Had a pretty good day and managed to keep everything under 3" @ 100M and 6" @ 200M. These were my best of the day. (btw...white squares are 2 1/2"x2 1/2")

Bill

Attachment 72943Attachment 72944

[HollowPoint]

Kraschenbirn:

Do you have any idea what kind of velocity you're getting with that charge weight?

HollowPoint

[Kraschenbirn]

Kraschenbirn:

Do you have any idea what kind of velocity you're getting with that charge weight?

HollowPoint

I've never chrono'd that load in the K-31 but 29.5 gr H4894 with the same boolit runs around 1950 fps in my .308s so I imagine the 7.5x55 is the same ballpark.

Bill

[mace2364]

OK, so I know you were asking about commercial lead bullets, which I haven't messed with in my K31. I did load some winchester 147gr jacketed in mine, using the lee dies. I put them over 42 grs of varget. If you don't end up with what you want for lead, you might try something like that.

[Smokepole50]

Has anyone ever considered sending a GP-11 bullet to NOE to have a custom K-31 VLD mold made for a GB?

Another thought, has anyone ever considered making a chamber cast and having a custom reamer made to give the K-31 a proper throat and lead for cast boolits? GP-11 won't be around forever. It could even be a group buy that could be passed around to all who pitched in for the custom reamer.

[uscra112]

Another thought, has anyone ever considered making a chamber cast and having a custom reamer made to give the K-31 a proper throat and lead for cast boolits? GP-11 won't be around forever. It could even be a group buy that could be passed around to all who pitched in for the custom reamer.

Ive thought about reaming mine, but in the end I have found a boolit that fits it. The downside is that it's an obsolete Eagan mould, no longer obtainable. Fortunately for me the owner of said mould has been more than willing to provide me with its' output, cast in Linotype.

And there's an NOE mould 311-180-K31 that is supposed to be specific to K-31s. I have one, but due to the above-mentioned kindness (and my current circumstances) I have not cast anything in it yet.

Any such reamer would have to have a live pilot, and be supplied with a range of bushings, since recent survey by madsenshooter has demonstrated that K-31s range from .298 to .301 bore diameter at the throat. (Mine is the one that's .301, BTW.)

[burt]

any one of many '30 cal' cast bullets should be fine....there's a bunch of 150/165 plain or bevel base that are sold by the internet vendors or by the manufacturer.
What 'length' .... remove the striker assy from the k-31... prepare a 'dummy' cartridge using the M die...just bell the case mouth enough to push the bullet into the case just enough to make sure you don't shave lead.
The cases must all be the same length!
Seat the bullet so it is way too long but try to close the bolt....no go? seat it a little deeper.
Turn the seated bullet against some fine steel wool so it is polished and try to seat it.... maybe a little deeper? You will finally get the bolt to lock up..... remove the dummy and inspect the bullet under low magnification...you will see the contact points 'engraved' in the bullet...polish them off and seat several thousandths deeper...repeat all this till the marks are very small.....
you might want to do this with several bullets....they may be different. When you are satisfied that you have found 'Zero', measure the o/a length of the seating die.... or... better yet, use a 'Redding Micrometer' seater... just read the settings. Final seating depth varies with each bullet profile and best accuracy could be with the bullet seated at/into the lands by a bit...it is a 'discovery problem' !
Don't go anywhere near any max loads! No purpose.....

Done.... while you are working this out...take a look at the way the K-31 bolt is put together!!!!!!!!

When all is done exactly right, you can expect 10 shots into an inch at 100 yds over bags. Enjoy....

[uscra112]

Sorry to have to disagree so quickly, but I've observed that "commercial" boolits in that weight range are virtually all possessed of a fairly fat forepart, designed for the giraffe-necked .30-30. They also fit the .30-06, which also has a neck long enough to handle this. Not surprising, since most .30 cal boolit buyers are shooting one or the other, or maybe a Krag, which will swallow almost anything. They are not so fine in the K-31, which has that short throat and only .300 of neck to work with. By the time you get them seated so you can close the bolt, they're so deep in the case that the gas check is dangling .100" or more below the neck.

[burt]

thought I indicated plain or bevel base????? Used these in several K31s and a Hammerli-K31 300 m.
Never tried to push it to the point of a gas check .... maybe prepare several loads???
The 'slow' load w/o gas check is fun to shoot offhand because of the long barrel time. Make them as slow as possible.... you will become an expert offhand...or you will give it up!!!!

[uscra112]

thought I indicated plain or bevel base????? Used these in several K31s and a Hammerli-K31 300 m.

Ah, so you did. My bad. My bias for 2K+ loads in the thing was showing.

[madsenshooter]

I haven't shot enough of the bullet to say how it will shoot, and it requires modification. But Lyman's 308329 with the front band bumped down to whatever your particular rifle needs, would be a candidate for the VLD mold smokepole50 mentioned above. Smoke em Joe makes a bump die to use in your Lyman sizer. After the bullet is checked and lubed you run the bullet nose first into Joe's die to bump the front band down. In my tight bore rifle it has to go down to .3055. Once that's done the ogive of the 308329 can be seated out into the rifling, and the bullet is below max magazine length in my rifle. I have some cast, but I have other projects going on right now, the biggest of which is getting loads for my Krag developed for the Vintage Match at Camp Perry.