Making brass for Swiss K31 and K11

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I haven’t taken out my Swiss K31 and K11 out to the range in a couple of years due to work obligations. I started looking for ammo last week and found none to be had ? I reload, but found that even 7.55 X 55 Swiss brass is almost impossible to find. What to do ? I searched the net and find that .284 Winchester cases can be used to make the Swiss 7.5 X 55 case. Just run the .284 cases into a Swiss 7.5 X 55 die they say. Yes – it can be done but not so easily. What you have to do is neck up the .284 diameter neck to accept a .308 bullet. If you try to do that with most dies, you might wind up with a flattened case shoulder because most expanders won’t allow a .024 inch expansion of the neck. You also have to bring the top of the shoulder down from 1.885 on the 284 Win case to 1.850 on the 7.5 X 55 Swiss case. The neck has to come UP and the shoulder has to go DOWN.

Get a new set of Lee 7.55 X 55 Swiss dies because all their newer dies have a nice gradual expander that can do that. My Lee dies (which were about 15 years old) had an older type expander that would not allow a gradual expansion of the case neck. I was able to pick up on Ebay a new gradual .308 expander for my Lee 7.5 X 55 resizing die. See photo above.

Lube up a .284 Winchester case on all exterior surfaces including the shoulder. Yes – You don’t place lube on the shoulder when you normally resize a case but remember the shoulder will have to come down about .035 inch and you want some lube on the shoulder. Also lube the INSIDE of the case neck. I used a small paintbrush to “paint” the inside of the neck with my Imperial Sizing Die Wax.

When the Lapua .284 cases that I used came out they had lengthened from about 2.163 inches to about 2.178. (about .025 inch) The “trim to” case length on a Swiss 7.5 X 55 is about 2.170 to 2.175 inches depending upon what reloading source you use. The 2.178 length fit perfectly into both a Swiss K31 and a Swiss K11 that I own. What I plan to do is fire the cases as they are now, full length resize them and then trim them all down to 2.170 inch.

Bob

Note - There is a head size difference between the .284 Winchester case and the 7.5 X 55 Swiss case. The .284 has a head size of .473 inch and the Swiss 7.5 X 55 case is listed as .495 inch. The Swiss case head is .022 inch larger than the .284 Winchester case. Even though the .284 case has a smaller head size, both of my rifles extract these cases just fine even with the smaller head.

Bob

At $1.50 each after taxes and shipping, I get a case of loaded Prvi ammo (plenty on GunBroker), and the brass is fully reloadable.

Yes - but I live in Massachusetts and unfortunately most online sellers will not ship loaded ammo to me.

Bob

You could start out with 6.5x55 brass as it's .480" at the Head Dimension.

However, you need the PPU, Lapua, Norma or some other European brand of brass, although Starline brass might measure out at .480" as well. The reason being is that the North American manufacturers "cheat" when producing 6.5x55 ammo and brass by using the .308~30-06 head size as they can incorporate it easier into their production lines. Thus the head size on their ammo and cases is the nominal .473".

A search for properly sized 6.5x55 will get you closer to your goal than .284 brass, but still not spot on.

As I mentioned above, the very small difference in head size between the .284 brass and the 7.5 X 55 brass (about .022 inch) doesn't seem to make in difference in my two rifles (K11 and K31). The Swiss brass made from .284 brass extracts just fine in both of these rifles.

Bob

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This topic is muddled by the use of "head size" for "rim diameter".

For those who don't know, the .284 Win. is a rebated rimless design, with the rim .473" max and the case's major diameter .500" max (just forward of the extractor groove). The major diameter is generally a hair larger than the average 7.5 Swiss case and first forming puts a lot of stress on sizer die and press - but the end result fits well in the usual 7.5x55 chamber, which generally measures about .502" at base.

The rebated rim normally works well with the K31 extractor and ejector. For the earlier models (1889, 96/11, 1911) a couple of careful modifications to bolt and ejector may be required for reliable function with the rebated rim.

Thanks for clearing up a bunch of misinformation from several people who did not know what they were talking about .

Been there, done that, no T-shirt.

When I got my K-11 about ten years ago, ammo was strictly a collectors thing. Lots of stuff is like that here in the Antipodes. The bulk GP-11 ammo that seems to have been briefly abundant in North America, came nowhere near her except in tiny lots.

So, having a few stray .284 Win cases, and fresh set of Lee dies, I went to work.

Formed and fired OK, primary extraction OK, HOWEVER, because of the rebated rim, ejection was "optional". Yes, it IS possible to "adjust" the extractor, but unless you are good with precision fitting techniques, give that a pass.

OK for plinking or very slow fire stuff, but not much fun during rapid or even "snap" matches. Eventually a source of Privi factory=fresh brass appeared, so I grabbed a couple of hundred. If the Privi cases are not readily available, 6.5 x 55 Swede is an option if you are keen on a relatively minor neck expanding and fire-forming exercise. 7.5 French cases are another option, also being very similar to their Swiss cousin. Unless you are running something belt-fed, a hundred cases will keep you busy and a spare hundred will contribute to a long shooting life.

One (universally applicable) caveat:

Because the case body of the 7,5 Swiss is fairly tapered, compared to "modern" designs, It tends to "flow", with neck-length growth apparent after even a few, "non adventurous" loading and firing cycles. This is no "bench-rest" chamber; the cases expand and when you FL size them, metal moves forward. Everybody reloading for any centre-fire rifle should own a case trimmer of some sort. (And actually use it).

None of the above is "rocket science". And a reasonable trimmer and associated gear is cheaper than a new rifle or a new set of eyes.

I just bought 100 7.5x55 cases from Grafs. No reason to make them from anything !