New Swiss K31 and reusing GP11 cases

[HammsBeer]

Wow, beautiful wood on that and the bluing looks new. Is it by chance refinished or a P prefix serial number, indicating a private ownership rifle?

Modern cost cutting measures probably put an end to the wax sealant.

 

[HammsBeer]

Tiger stripes...

 

[lonniemike]

bi-metal jackets like the US national match stuff in the 30's fouled badly and caused pressure problems. These same kinds of problem were found in some Danish bi-metal surplus ammo in 6.55X55. The bi-metal was a nickel clad steel jacket in both cases. The Swiss never used a (hard)nickel clading in GP11 but a very soft Cu(83%)/Ni(17%) alloy as a clading. As far as I know fouling in the Swiss rifles is not a problem. Nor have I heard that the Swiss had pressure events from nickel welding of bullets to cases. The US did study/copy the GP11 projectile somewhat way before 1930. And if the US Nat Match ammo was bi-metal, then the Swiss projectiles are and have been tri-metal.Best

 

[lencac]

Hamms, nope I think it's a normal service rifle that probably was never put in the field. It does appear to be as new both cosmetically and mechanically.
I really like your tiger stripe K31

Good info. lonnie

 

[Trent]

F-Guffey on this board knows quite a bit about the cold welding phenomenon.

Slamfire has done quite a bit of research on it too.

Stealing a passage he quoted on TheFiringLine since it's relevant to discussion:

Previous to Hatcher’s Notebook is Major Earl Naramore’s 1937 Book Handloading. http://www.castpics.net/subsite2/Cla...20- 1943.pdf . In the 1920’s , Major Naramore is a frequent contributor to Arms and the Man. He is a true expert ballistician, a truthful man, and I expect his 1937 book was written close to or after his retirement. And this is what Major Naramore says about the tin can ammunition:

"Page 159
The ammunition made a Frankford Arsenal for the 1921 National Matches had bullets heavily plated with tin. This ammunition was satisfactory when first loaded. Tin has an affinity for brass and in this ammunition the tin combined with the insides of the case necks, forming a union between the bullet and the case just as though the bullets were soldered in place. This union is so strong that it is impossible to extract the bullets and if the ammunition is fired, dangerous pressures will develop. Most of this lot of ammunition, the only one so loaded, has been shot or destroyed, but anyone running across any of it should destroy it or preserve it only as a curiosity in the development of ammunition It should under no circumstances be fired. The marking on the case heads is, F.A. 21-R"

more discussion here; http://thefiringline.com/forums/showthread.php?t=528373

 

[barnbwt]

The only GP11 kaboom I've heard of was an STGW57 autoloader, and that was due to gunk in the locking recesses preventing full roller engagement under pressure (oil was being used instead of grease). The K31 likes grease, as well (I suspect GP11 does, too).

TCB

 

[lencac]

Hey Hamms if you liked my last one then you will probably really like this one
I'm sure it was unissued and never used, maybe only test fired because it is totally unblemished in any way showing zero signs of even having the action cycled.

 

[zfk55]

The rounding of the fingergrooves tells the tale. It's very likely been refinished, but if you post the serial number I can tell you for sure in minutes. Do you have a closeup of the front sight and sideview of the buttplate?

 

[HammsBeer]

Good to hear that the cupronickle is less prone to fouling. Sounds like it's a bit softer metal and easier on the barrel.

lencac, that is in immaculate condition! I'd assume you don't shoot that rifle. My '51 beechwood was amature refinished by previous owner, but shoots great.

 

[HammsBeer]

What grease have you guys been using for the bolt? I've been using proshot progold grease, but I'd like to use a more authentic grease issued to Swiss troops or modern equivalent.

 

[Swampman]

Originally posted by: lonniemike

These same kinds of problem were found in some Danish bi-metal surplus ammo in 6.55X55.

This is unlikely since the Danes never used 6.5x55. They adopted the Krag firing the 8x58R cartridge in 1889 and used it until it was replaced by the M1 Garand in 30-06 after WWII.

 

[lonniemike]

Swampman, you are right in that the Danes did not use the 6.5X55 round but apparentlly the Danes did make/sell ammo to the Swedes and/or Norwegians. There are more than one admonishments not to use the 6.5X55 Danish ammo. You may find one at ParallaxBill's Swede Forum.
HammsBeer, find Guisan's email and order Waffenfett(yellow) or Automatenfette(black) from him.

 

[lencac]

Zfk55 here's a couple photos
The serial # is 962880

 

[Matt Dillon]

I use the Swiss Autometenfat in all my arms, Swiss or otherwise.

 

[barnbwt]

Finally got my STGW ready for test fire (maybe when the roads clear --of idiots-- after the ice melts). I think I'm gonna paint it semi-gloss black on all darkened metal surfaces.

I also had an idea for Boxer conversion that I wondered if you all had ever heard of; grind the end of a Boxer-diameter endmill to the flash hole diameter, and drill out the spent primer and hole with the same operation on a drill press (probably securing/jigging the case in a sizing die clamped to the table). Seems a hell of lot easier than hydraulic primer removal and three separate machining operations

TCB

 

[lencac]

Trust me, the RCBS berdan primer tool works like a champ.
I decapped 60 GP11 cases yesterday, took less than 10 minutes. No muss, no fuss, no mess

 

[lonniemike]

barn, if one does your process, then you've a case with no anvil to strike on a berdan primer and a boxer single (actually3 holes) flashhole in a case which will not hold in boxer primers. Sure, it would be a snap to pick out the spent primers, so what am I missing? My thinking cap hurts.

 

[barnbwt]

Why wouldn't a simple hole retain a Boxer primer? Pretty sure my Winchester brass has primer pockets that look like that . Any conversion of Berdan to Boxer (as is done by really cheap people currently) results in 3 holes, and it seems to little detriment (it's not like that thin, perforated web is holding back pressure in any case). In case I wasn't clear enough in my first post, the ground endmill is a stepped profile (drills flash hole and counterbores the primer pocket to the appropriate size simultaneously)

1) Insert round into jig
2) Bore out primer/pocket/flash hole
3) Size/prime/load

or

1) Hydraulically or manually remove Berdan primer
2) Insert round into jig
3) Mill away anvil
4) Drill flash hole
5) Size/prime/load

Yes, reloading the Berdan primer would be the easiest solution, but those hardly ever exist over here (I'm still not sure why on one's begun making them by now, since there is a pretty good demand out there). Obviously the conversion only works on cartridges with Berdan primers small enough that the hole can be enlarged to the appropriate Boxer primer (I believe GP11 can be converted to use standard large rifle primers without issue), but I think it could be incorporated into any progressive or manual press --just need a flex-shaft driven rotary tool bit in place of the primer holder and decapping pin on the retract of the sizing stroke

TCB

 

[lonniemike]

Berdan case 5.5mm primers are about .217" in diameter. The large boxer primers are about .210" in diameter. You got to squeeze the case some, or use glue, shims, maybe chewwing gum to hold in the boxers or they will fall right out. I've tried three out of four methods. GP11 uses the 5.5mm primers (.217") Best

 

[Trent]

Barn; the 7.5 Swiss Berdan pockets are larger diameter than our large rifle primers.

Primers in stock here;

http://www.lohmanarms.com/product_p/takv762nb.htm

These are the same dimensions as RWS 5620 berdan primers which are "correct".

 

[Trent]

Graf & sons has cases of them too.

http://www.grafs.com/retail/catalog/product/productId/23431

With Hazmat at Grafs it comes to $0.04 per.

 

[Trent]

It was easier, by far, to find Berdan primers during the "GREAT RELOADING SHORTAGE OF 2013" than it was anything else, BTW.

 

[barnbwt]

"Berdan case 5.5mm primers are about .217" in diameter. The large boxer primers are about .210" in diameter."

Dang, I mis-underestimated them! That's for sure close enough that light swaging would secure them, but again, extra steps are to be avoided here . 50BMG primers, anyone? Wouldn't need powder! Also, the GP11 apparently has deep enough pockets that the case anvil can be squashed to create clearance for the Boxer anvil. That operation could at least be combined with the swaging of the pocket, but you're still back to manually removing the spent primer.

"It was easier, by far, to find Berdan primers during the "GREAT RELOADING SHORTAGE OF 2013" than it was anything else, BTW."

Well, so was a functional machine gun compared to a nuclear bomb in WWI, but a fat lot of good that did the French . What kind of standard is that to judge scarcity by? Still no powder (of any sort ) at the local BP, btw.

So, do Berdan primers have only a few standard sizes? I always figured every country (or heck, every ammo plant) had their own size. I've never really sought after them, but I've only ever heard from local places that the quantity of Berdan primers floating around is consistently minimal.

TCB

 

[Matt Dillon]

I have quite successfully used PMC Berdan primers in GP11 cases, using the hydraulic method to remove the original primers.

 

[lencac]

This thread has taken on a life of it's own

Lonnie is right. Berdan and Boxer have different diameters, .007 in. to be exact.
Why do you suppose that is

So bananaheads don't do what you are talking about doing, jeez:banghead:

If you're going to do the job just belly-up to the bar and do the job right.

Anything else is dangerous

Listen-up people

Get the RCBS decapping tool and a RCBS hand priming tool and modify it like I've have already showed y'all. Fix the sizing die and just do it
Go big or go home