New Swiss K31 and reusing GP11 cases

[barnbwt]

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

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

Anything else is dangerous"

Uh, wha-huh? Too many euphemisms. Are you saying that a primer pocket can't be swaged .007" to fit a Boxer, because it's been done successfully by numerous folks without issue --it's just not practical. Not when Starline sells new brass. Obviously if that ever ceases, then converting the cases makes a little more sense (not much more, though ). If 7.5x55 ran at 5.56 pressures, I might be a tad warier, but it don't (quite). Many success stories of it being reloaded numerous times and the primers staying tight.

Until Starline/etc. ceases production, the most economical use for GP11 brass is to sell it to dummies who want to try converting it (or to the lucky/wise few who managed to stock up on Berdan primers and who care to manually remove them). At least I can rest easy knowing the stretched out, fluted, bent up, double-shouldered GP11 brass ejected from the STGW57 will be utterly unusable . No temptation

TCB

 

[Trent]

No, not "swaged to fit a boxer". It starts life "too wide for a boxer primer".

The cup of the 5.5 is .007 too WIDE and .007 too SHALLOW.

One of those is easier to solve than the other.

You seat a boxer in there without a shim around it, gonna have a bad day when that bugger pops out on you. (You'd still have to ream it .007 deeper, which will also weaken the head further, which will have an additional big hole in the middle of two smaller ones).

Point being a LOT more backpressure is going to hit the primer due to the extra ventilation, and that boxer isn't going to seal tight.

The two of those phenomenon combined is not going to work well.

 

[lencac]

Listen to trent ................ he knows of what he says.

Besides I've given y'all the keys to the berdan kingdom .................... let's take 100 used berdan cases. Someone say "GO!"
Now let's see who gets 'em decapped and has his mess cleaned up first ................. oh wait, my way has no mess no drill, no swag, no water, no doubt

Read 'em and weep

 

[lonniemike]

No, not .007" deeper but about .045" or so deeper!!!
Check out ParallaxBills handloading forum for showing a berdan to boxer converation(squeezing) process and discussions. In the early 60's, berdan stuff was mainly foreign and probabally "commie" so everyone hated reloading for it. I did a lot of adaptive experiments. Now as long as Boxer sized brass is available and berdan primers are also available, It just isn't worth the time or hassle to mess with any conversions these days.
Has anyone searched and found Parashooters no water(and fast) berdan decapper? Look search around SwissRifles.com posts and pics on many Swiss items and subjects of interest.
I don't use/have a 57, but I think a number of people can and do reuse the spent 57 brass. I would use brass until it get incipient seperation signs. There are 3 sizes that I know of in berdan:small .210, med .217, lr .254. There may be other dia sizes and my dias are from recall and sketchy at best. And there are cup height differences for different pocket depths. Plenty of varibles.BestAll

 

[lencac]

HELLO ........ is anybody home ............... pay attention:banghead:................ I just showed you all exactly how to do the job properly, fast, efficient and quick .............. it's easy



But if you want to continue to beat a dead horse

 

[barnbwt]

"HELLO ........ is anybody home ............... pay attention"
"But if you want to continue to beat a dead horse"

No, we want to use Boxer primers --pay attention!

"It just isn't worth the time or hassle to mess with any conversions these days."
Amen, +1 kudos big ups. We live in a glorious renaissance of the 7.5 Swiss, in which K31's are now cheaper than Finnish Mosins, let alone Mausers, ammunition is available in quantity for less than 308, receiver repair sections for STGW57 parts kits are being made, and numerous companies the world over are producing brass and cartridges.

I honestly wonder if we aren't on the edge of it becoming, if not mainstream, at least recognized, as a more efficient alternative to 30-06. Hopefully someone will start reproducing GP11 bullets, too, so we can enjoy their insanely-long ogivey goodness with superior ballistic coefficients.

If things ever return to the bad old days of a decade or so ago, wherein I am told there was so little ammo to be had that the rifles were practically given away --to few takers-- we will begin to weigh whether or not a Boxer conversion v. Berdan setup is preferable. Personally, I shoot so much more 7.5 than anything else these days (and the semi auto won't help that one bit), that being able to run the spent cases through a progressive setup would be very attractive at some point.

In the spirit of reusing/converting spent GP11 brass... Anyone know of a way to put a blank-firing crimp on the cases? I scored a couple Energa practice grenades, and it'd be super cool to play grown up lawn darts sometime, but I'd obviously want to approach to matter properly (with the right cartridge construction and propellant). To my knowledge, grenade-blank 7.5x55 (called ubermensch-patronen or something like that) does not currently exist over here, and I doubt it ever did, so there's little alternative but to convert spent 'live' ammo.

TCB

 

[Trent]

I scored a couple Energa practice grenades, and it'd be super cool to play grown up lawn darts sometime, but I'd obviously want to approach to matter properly (with the right cartridge construction and propellant). To my knowledge, grenade-blank 7.5x55 (called ubermensch-patronen or something like that) does not currently exist over here, and I doubt it ever did, so there's little alternative but to convert spent 'live' ammo.

TCB

That's an interesting topic.

BTW, where'd you get the practice grenades? I want me some of those.

 

[lencac]

No, we want to use Boxer primers

But that would be stupid and unnecessary

but I'd obviously want to approach to matter properly

Is using drilled out berdan cases that have to be crimped to keep the boxer primer from falling out considered "proper"

I must not being paying attention


Barn but that is a good observation about the popularity of the K31's. I'm somewhat surprised they have been overlooked in this country for so long. Absolutely wonderful rifles.
I had one about 20 years ago but didn't really appreciate it for its intrinsic qualities. Probably because the stock was kind of beat so I lost interest in it and sold it. I think I paid like $100 for it at that time.

Also another observation I made about the rifle is that not only does it utilize the rear of the receiver (the trigger housing) for the load-bearing lug but the whole receiver is virtually free-floated in the stock. Only the rear tang/lug and where the front screw bulkhead meets the stock does the receiver contact the stock.

 

[lonniemike]

I like to visit other sites like this one, but home base for Swiss info is SwissRifles.com and the discussion forum. Not that one can't find info elsewhere but this is home to the likes of Parashooter, Guisan, Pierre and Latigo(SwissProducts), BobS, myself, and many other Swissers. I say again come and look around a lot.
Barn,we've had discussions on blank forming that may interest you along with a pictorial by Para's no water lever out the primer. More much more BestAll

 

[lencac]

Here's a link with some stuff
http://www.thehighroad.org/showthread.php?t=739329

 

[MJ]

Very interesting post and finally thanks for the primer links. How about a link for the Senecar L bullets.

Cheers

 

[SSGJ]

Where to find once fired brass?

I am new to the forum, so apologize if this has been covered. Does anyone know where to find 7.5x55 brass? I cannot seem to find any used or new.

 

[barnbwt]

Starline makes it, unless they've been diverted into 223/9mm production these days. Hornady and a few other companies have used Graf's brass, I'm not sure if they are still producing now, though.

TCB

 

[barnbwt]

Just for fun's sake, here's what the GP11 brass out of a STGW looks like compared with that from a K31

...


...ewwwwww

That said, it's probably still perfectly safe, though I'd probably put it in a bolt action hereafter if anything. I think rounding off the ejection port will smooth out that dent some more, and the double shoulder will still function as before as far as headspacing is concerned, but it won't allow the ammo to cushion the bolt as it slams home if I put it through the 57 again.

TCB

I picked up the 243WSSM case at the range since I thought it looked funny

 

[Swampman]

Originally posted by barnbwt

Starline makes it, unless they've been diverted into 223/9mm production these days.

To the best of my knowledge, Starline does not make, nor have they ever made 7.5x55 Swiss brass.
They may have listed 7.5 Swiss pistol brass at one time, but I'm fairly certain that no such rifle brass has ever been manufactured by Starline.

Prvi Partizan, Norma, FNM, Hanson (made by Prvi), Graf & Sons (made by Prvi), Wolf (made by Prvi) and Hornady (again, actually made by Prvi) have all sold Boxer primed ammo/brass in the US, there may be others, but I don't think Starline is among them.


Originally posted by barnbwt

Hopefully someone will start reproducing GP11 bullets, too, so we can enjoy their insanely-long ogivey goodness with superior ballistic coefficients.

They already have:

http://www.midwayusa.com/product/62...r-175-grain-hollow-point-boat-tail-box-of-100

It actually has a higher BC than the GP11 bullet and is capable of tighter groups. The only problem is that the Berger BULLETS cost about as much as GP11 AMMO!

I can state unequivocally, that the most accurate long range 7.5x55 ammo I've ever shot was loaded with the above bullet in GP11 cases with a stiff charge of RL-17 sparked off by Murom KV-7.62N primers. The only case prep needed was to drill the flash holes slightly larger and they outshot fully "match prepped" Norma brass.

To me, that's a good enough reason to go to a little extra trouble depriming the GP11 cases.

 

[HammsBeer]

MJ, that tiger stripe is stunning!

 

[lencac]

Swampman, just curious, how much RE-17 are you putting in that load ?

And what size drill bit are you using to open the flash holes?

I came up this a load for Hornady 150 gr. FMJ, 51 gr. RE-17 in GP11 brass. It was generating right around 2840 fps and was extremely accurate. At least at 100 yrds off the bench with match diopter sights

And MJ's tiger stripe K31 is freakin awesome

 

[Trent]

Just for fun's sake, here's what the GP11 brass out of a STGW looks like compared with that from a K31

Holy shoulder stretch, batman. I think it's safe to say where the eventual failure will be after it's been resized a few times.

 

[lonniemike]

Where is that Trent? I say the rim about 1/2 to 3/4" up from the base from incipient or complete case separation. Annealing should take care of any shoulder or neck splits. Eventually all the case trimming catches up and a thinning ring will develop.Best

 

[barnbwt]

"Holy shoulder stretch, batman."
There's almost no stretch, in fact. The shoulder looks weird because the chamber is weird. There is a second shoulder which swages the chambering round, cushioning the bolt carrier in the process (probably very helpful on full auto, I'd imagine). Look at the base of the actual neck, rather than the corner of the shoulder, and you'll see there is very little stretch (it's less than .01" as I can tell visually). As for the ring toward the base, that's on the K31 brass, too (and on the unfired brass, as well, suggesting it's from factory sizing dies). It's hard to see, but the reflections on the case also show a near zero depth on the flute markings (except at the second shoulder where they are in stronger relief).

I do agree that popping the second shoulder in and out repeatedly by alternating STGW and K31 would probably not be the best idea . I imagine it could be reused in the STGW with no ill effect, but that cushion effect would not be present (and is rougher on the receiver welds which I'd rather not have to address again )

TCB

 

[lonniemike]

Ironing out the shoulder or neck areas by firing, annealing, and resizing should not give one problems.
The shiny ring from resizing is completely different than an incipient case separation. As you shoot and trim to lenght repeatedly, that trimmed neck brass has to come from somewhere. Looking inside an empty a thinning ring can sometimes be found near the base. A bent paper clip can be real useful to feel this ring without seeing the ring. It is possible to shoot factory ammo and get an incipient separation on the first firing as I did a long time ago with some PMC Swede ammo. Seriously bad ammo that stuff was. But repeated use, oversizing, oversize chamber, and etc will lead to the internal ring. It is always bad. That shiny spot on the outside by itsself means nada.Best

 

[lencac]

Hi Lonnie:
That's good info. I have had over the course of many years had only a few case separations where the cup meets the shell. A broken shell extractor comes in really handy when that happens. I try to keep track of how many times I use a case and I keep my brass in 50 case sets. If I get a neck split or a case separation for no other reason than use I will ditch the whole 50 case set. Careful inspection of the cases is important also, both before cleaning a sizing takes place and after. Inspection is how I find virtually all failed cases.
You mentioned several reasons how case separation is expedited but one you missed that is also of import. The extraction process of semi-auto firearms will likewise expedite case failure. Some types of rifles are far more gentle than others. AR's and M1 Garands and M1A's have a relatively gentle extraction process. But cases used in semi-auto firearms I still use less than in turn bolt rifles.
Although, just because it's a turn bolt doesn't mean it's tight.
Here's a couple photos of a Norma case out of one of my Mosin 91/30's. That case was used only 3 times.

 

[lencac]

Just to keep the thing going here's a few photos of my latest K31 restoration.
It's beech wood, I think 1955 manufacture. Mechanically it's near new with a Hammerli premium barrel installed that is as new also. However, cosmetically it looked like an old man. The rifle must have been handled quite a bit as the metal bluing was maybe only 60 to 70%. And the stock has no cracks or fatal damage but it had quite a bit of just plain ole' grime in the spots that the finished had been worn off.
So in short if you had seen it as I received it and now you wouldn't know it's the same rifle.
I had all the blued metal professionally Cerakoted in graphite black. And the metal in the white I detarnished and put a little shine in it.
I check headspace and assemble checking for proper bedding and barrel preload in the stock.
I think it came out pretty well.
I've put together a number of these recently and I think I'll need to do something with a few of them.

 

[lencac]

A few more

 

[masood]

Something is off in your measuring - are you sure that's the correct gauge for that bullet (Hornady's/Stony Point A, B, etc. designations)?

A typical 150 FMJ won't close with an OAL greater than about 2.92 - the GP-11 is much longer as they use an extremely pointed - long nose - bullet profile. There's a Berger VLD that seats as long as GP-11 but I've never seen anything else come close.
/B

I used berger 168 vld bc. G1 .498 to OAL of 3.03 max . 2.99 to 3.03 with good fit. 3.06 ceated a bad jaam.

I used Fed mag primer and h-4831SC goof grouping at 100 yards but chorno give and ES of 110 in 20 shots with Avg velocity of 2042 fps. Hogdgon lists 2477 for 45 gr start load of h4831. My max speed was 2095.

Dunno why i do not get the speed i am aiming at. Now i weighted my ppu brass and bullets for uniform loads and will chorno test again to see if any inprovembet in speed and ES.

Any feedback appreaciated.

Swiss k31
Masood