Swiss K31: Check new brass length after its first firing & resizing

[mike in co]

Mike in CO -

On the tangent - I can see it useful to be able to neck size with the Redding FL die, though you could buy the Lee FL and neck for half the cost of the Redding FL - and simply dial the neck sizer out to get your 2/3rds.) Actually - if I necksize my swiss, I'll use my generic Hornady 30 cal neck sizer - I've had great luck with that.

this is not from someone elses info...this is my personal work....four k31's and purchasing all four sets of dies.......

you cannot dial back a lee(lymann, or rcbs) 7.5x55 die and NECK SIZE.....it will not work...it will size the body of the case long before you get the neck 1/2 sized.

the hornady neck size should work ok.


mike in co

[mike in co]

Geez this is a confusing thread!! Here are my experiences:

I have two sets of dies: A Lee collet neck sizer and seater, and an RCBS FL die and seater. I size with the Lee collet and seat with the RCBS. Tomorrow will mark the 1 year anniversary of my delving into High Power shooting which I have shot solely with a K-31. I shoot a very light load and of the 90 cases I haved used for competition over the last 12 months, I have lost exactly two cases, both of them to split necks. I have yet to trim a single case since the initial trimming and have yet to FL size any of the cases.
My normal procedure with new brass is to first trim all the brass to the same length. I never, ever use new brass without first trimming it. Next I load it so that whatever bullet I'm using is firmly into the rifling when the round is chambered. That way after the first firing, that brass all fits that chamber perfectly. When it becomes does become necessary to FL size, such as when I fire heavy loads with jacketed bullets, I use a method described in Handloader Magazine by John Barsness. Here is an excerpt of that article from an internet site:

"....In making straight ammo, there are better tools and methods than the average neck-sizing die. All the full-length dies I've tried in the past decade size cases straight, but more often than not, the expander ball pulls the neck crooked. Sometimes this is because the "ball" (actually a cylinder of some sort) is mounted crooked on the decapping pin. Expander-ball/decapping-pin straightness can be measured with a concentricity gauge, and corrected with the judicious use of pliers.

Sometimes, however, even a straight expander ball pulls necks crooked. The only solution I've found is to unscrew the expander, fully size the case, then screw the expander assembly back in the die and "push" it into the neck of the sized case. For some reason, this almost always results in straighter necks."

We've all seen necks "pulled" longer when the expander ball exits the neck. The above described method all but eliminates this. The article in its entirety can be found in one of the 2006 (IIRC) issues of Handloader and is one of the best article on handloading I've ever read and goes into much kore detail than the above excerpt.

35W

yep no issues with this process.....the collet neck die is not a fl sizer, so no issue there.
i would suggest that since you are having good luck the way you do things, that when you get to the point of needing to push the shoulder back, you use a k31 die and not a 7.5x55 die. yes both will work, but under sizing with a 7.5x55 is counter productive to keeping the brass in use as long as possible. consider annealing to minimize/eliminate the neck splits.

and yes i do not PULL buttons thru any of my brass.....

mike in co

[Storydude]

I cannot see the big problem in tossing a piece of brass(which is designed to be a disposable commodity) when the situation warrants.

I see reloaders trying for save that one piece of brass for 200 firings. I look at tossing brass as a part of reloading. Sure, you might save a piece for another 2-3 loadings, but at what cost? More work? more stress? worrying about if it'll chamber?

Just because a person can get 3 more loadings from a piece of brass, is that worth getting all bent out of shape over?

[mike in co]

I cannot see the big problem in tossing a piece of brass(which is designed to be a disposable commodity) when the situation warrants.

I see reloaders trying for save that one piece of brass for 200 firings. I look at tossing brass as a part of reloading. Sure, you might save a piece for another 2-3 loadings, but at what cost? More work? more stress? worrying about if it'll chamber?

Just because a person can get 3 more loadings from a piece of brass, is that worth getting all bent out of shape over?

sorry but what are you talking about ??? 2-3 to 200 is a bit of a generalization..

yes brass is a disposable part of loading, but when one pays close to a buck a pc...you want a reasonable lfe out of it..it aint like tossing a 9mm or 40 s&w case....

and this is a unique situtation.
the swiss use one cartridge...that happends to fit two DIFFERENT swiss chambers. no other cartridge, that i know of, fits two rifles....( i said "fits"...not capable of being fired in).

its about getting "acceptable" life from a pc of brass....

when done properly i have seen 308 win go FIFTY reloads...it would benefit from neck annealing in the end.


so..."two or three more " from how many ??.....10-12 from my norma at full powder loads in a k31 will be fine with me...and i would never get them from a 7.5x55 fl die.

mike in co

[Linstrum]

Yup, Mike, you expressed my sentiments quite well.

rl728

[Bob S]

This guy "Denver Dick" has gotten 19 load/fire cycles from Norma cases in K31's using RCBS FL dies:

http://theswissriflesdotcommessagebo...46#reply-12046

I know he had a "triumphant" post when he got to 20 with that lot of Norma Cases, but I can't find it. May have been a different board.

Re: neck sizing:





My favorite tool for loading most cast loads in most cartridges is the Ideal/Lyman family of "nutcrackers". Of course they never made 7.5 x 55 dies for the No. 3 or 310 tools, but 30-06 dies are ubiqutous even today, and several years ago I altered a set of 30-06 dies by shortening them and opening them up slightly with the .30-284 chambering reamer, and using the .284 "insert" in the handles. I have restricted neck sizing to light cast loads only for the straight-pulls as the neck sized cases from full-power loads chamber with resistance after the first firing. YMMV .....

Resp'y,
Bob S.

[mike in co]

This guy "Denver Dick" has gotten 19 load/fire cycles from Norma cases in K31's using RCBS FL dies:

http://theswissriflesdotcommessagebo...46#reply-12046

I know he had a "triumphant" post when he got to 20 with that lot of Norma Cases, but I can't find it. May have been a different board.

Resp'y,
Bob S.

you forgot to mention...that he was annealing EVERY FOURTH time.....does make a difference.


mike in co

[Storydude]

sorry but what are you talking about ??? 2-3 to 200 is a bit of a generalization..

yes brass is a disposable part of loading, but when one pays close to a buck a pc...you want a reasonable lfe out of it..it aint like tossing a 9mm or 40 s&w case....

and this is a unique situtation.
the swiss use one cartridge...that happends to fit two DIFFERENT swiss chambers. no other cartridge, that i know of, fits two rifles....( i said "fits"...not capable of being fired in).

its about getting "acceptable" life from a pc of brass....

when done properly i have seen 308 win go FIFTY reloads...it would benefit from neck annealing in the end.


so..."two or three more " from how many ??.....10-12 from my norma at full powder loads in a k31 will be fine with me...and i would never get them from a 7.5x55 fl die.

mike in co

Paying a buck a case is a choice you make. Actually, the GP11 cartridge fits and can be fired from 3 rifles. 1911, K31 and StG 57, All with different chambers.

I feel acceptable brass life(again, considering it's a wear item in the whole machine) to be 3-4 full power loads, assuming I can find it after It's fired.

YMMV.

[Bob S]

you forgot to mention...that he was annealing EVERY FOURTH time.....does make a difference.


mike in co

I used to anneal after every fifth firing. Now I do it closer to every tenth: getting lazy in my old age. Yes, it does make a difference.

Resp'y,
Bob S.

[mike in co]

Paying a buck a case is a choice you make. Actually, the GP11 cartridge fits and can be fired from 3 rifles. 1911, K31 and StG 57, All with different chambers.

I feel acceptable brass life(again, considering it's a wear item in the whole machine) to be 3-4 full power loads, assuming I can find it after It's fired.

YMMV.

you have to go back to the very begining of this k31 die issue..
i had my first k31 and there was no brass available...everyone was out, and no 284 to convert either....

the only brass available was norma......yes i made a choice to pay for it...i also made the choice to use the CORRECT die to extend the life of my expensive brass......throwing brass away after 3-4 loadings is a waste of good brass. throw it away when the necks loose tension...or they start spliting, i dont have a stretching issue as i don't over size the brass to begin with. i do not anneal at this point , so it gets tossed when it won't work anymore, not before.

3-4 is the number passed around by high powder shooters from the mil days of '06 and 308.....it just aint so...unless you abuse your brass with improper use of a fl sizing die.

mike in co

[mpmarty]

My first S/R rifle was an 1889 with the twelve round magazine. Bought from Martin B. Rettings in Culver City California in 1957. Had plenty of cheap Swiss ammo (pre GP11) with the long round nose. Bought a set of RCBS dies for it. Five years ago I bought a couple of K31s and have been shooting high power with one of them. In measuring my fired cases and then the full length resized cases I found way too much brass movement. I called RCBS and spoke to a gentleman there who was aware of the problem and said that for fee they would cut a custom die for me if I sent them a few fired cases. After he told me the "fee" I ordered a Redding die from Midway. All is good now.

[chasw]

I use Redding dies for my K31. My brass is a small lot of FNM, left over from some factory rounds. As I do with all bottlenecked cartridges, I use a full length size die, but only push the cartridge in as far as it takes to barely kiss the shoulder. When you look at a cartridge coming out of the die that adjusted this way, you can see where the die does not squeeze the lower half of the case at all. My practice is to measure all rifle cases every time they are resized. These 7.5 Swiss cases do seem to grow faster than other cartridges.

Fortunately, my K31 digests these "half sized" cases just fine. What K31s are fussy about is OAL. Most j-bullets have to be seated very deeply, cast bullets even more so. The only pills that allow a near normal seating depth are the VLD designs, one of which is loaded in the GP-11 Swiss military round. - CW

[AzizaVFR]

What powder charges and bullet weights are you using. Since the magical chamber pressure number for the K31 with GP11 is 45,500PSI, a perfectly safe full power reload should be set at 45,000PSI. Now you are asking yourself how can I get that precise considering how little reloading information is available for this round. I personally have used the program, Load from A Disc to help formula, test, and verify these kind of reloads. Within its database it has the 7.5x55 GP11 cartridge in its database. It is fun to do the "what if I use..." scenarios for various bullets and powders. After firing, the only sizing that is required is to use the Lee Collet die to reform the neck, then get ready to reload.

So far I have found to different powder combination behind a 175gr Berger VLD that duplicate the GP11 muzzle velocity and almost the same trajectory. I need to place the chronograph at 100 yards to verify the downrange speed difference between those silver bullets and the Bergers. The GP11 projectile was and still is a surpreme long range unit.

[JSH]

Bob, sorry this is so late, must have gotten side tracked.

Jeff,

I may have been one of the "well-meaning individuals" who told you it won't work. But I actually own a Winchester Model 70 chambered in 30-284; and in the real 3-D world, I can tell you that none of my 6 K31's, 2 K11's 2 96/11's and 2 1911 long rifles will chamber a 30-284 case because the headspace datum is about .015"-.020" longer than the 7.5 chamber. There is obviously less body taper on the 30-284, but the K31 chamber might tolerate that if it were not for the difference in headspace; the 1911 chambers would not. I have not tried to chamber a 30-284 case in either of the 1889's, or the Furter-Olten.

Bob, sorry this is soooooooooooo late
I looked at the K31 chambering of the 7.5x55 to be a sort of a minimum spec on a 30-284. As mentioned, the 30-284 will and can be spec'd out a lot of different ways. As are most wildcats.


If I may ask, has your carbine ever been checked with 7.5 headspace gauges, or 284 gauges (30-284 and 284 use the same gauges)? What brand are your 30-284 dies, and were they purchased new?

no on headspace
dies are a set of lee custom shop, they were brand new when purchased

K31's that have been rechambered to 30-284 do exist: see the 10th post in Buckshot's thread. The French could not own the K31 (or any milsurp, I think) in any military chambering; the quick fix to skirt that law was to rechamber them in the 30-284 commercial "wildcat". I saw one of these "French" K31's on this side of the pond many years ago, before K31's were commonplace, but I was not interested enough at that time to note if the carbine was marked to indicate the rechambering.

I suspect that if a guy faced .015-.020 off the base of a 30-284 die (or the shell holder) to get the correct headspace, it may work with a 7.5 K31 ... the result would be similar to the Redding "special K31" dies. I also suspect, but have not tried it (and have no motivation to do so), that a 7.5 x 55 cartridge could be fired in a 30-284 chamber without major discombobulation, if the extractor held the cartridge to the bolt well enough to get a good firing pin strike, or the bullets were jammed into the lands to hold the base of the cartridge against the bolt face at ignition.

If it's working for you, that's great ... but 30-284 will not chamber in any of my 7.5x55 chambers, and "neck up and shoot" 284's doesn't work in my rifles, either. And that's not based on just paper.


Bob, no offense taken and none meant here either, just a discussion.
When you mention the 30-284 will not chamber in your rifle. I presume you are speaking of a piece of brass that was shot in a 30-284 chamber?
I found this thread once again by accident. Summer is on us and wanted to refresh my memory.
I have a friends K31 at the bench along with his brass of reformed 284 and boxer primed 7.5. I ran it ALL through the 30-284 FL die. Just changing shell holders and bottoming out on the die. It just kissed about 1/2-3/4" above the web on all of them. I smoked one case then used a loop to look at the rest. I have no measuring tools to measure such a slight difference. However it does chamber noticable easier than a neck sized or unsized piece of brass.
FYI, the smoked case was marked all the way a round, so it just didn't drag the soot off of one side from friction. I size as much by feel as anything. There was a weee bit of resitance around the web.
I look at the 30-284 die as a large or standard base body die. Though it does size the neck at the same time and just kisses the neck shoulder junction. I do need to measure some of the mil ammo shoulder comapered to what it bumped at.

One last thing on annealing. I used to anneal only when necks sooted. I am know more towards some type of regular schedule on most everything. Yes it can be some what of a pita. But I take pride in my brass. It is as clean as it was when new and maybe even more. When I was still shooting the 7TCU, i was warned that milsurp brass was junk and should use commercial. Well, I found the exact opposite. I used LC 223 brass and had one batch of 250+ that are well over 25 loads and have been annealed numerous times. I am playing with a 6.5TCU and all of those were have been sized down from the 7.
jeff

Resp'y,
Bob S.

[madsenshooter]

What powder charges and bullet weights are you using. Since the magical chamber pressure number for the K31 with GP11 is 45,500PSI, a perfectly safe full power reload should be set at 45,000PSI. Now you are asking yourself how can I get that precise considering how little reloading information is available for this round. I personally have used the program, Load from A Disc to help formula, test, and verify these kind of reloads. Within its database it has the 7.5x55 GP11 cartridge in its database. It is fun to do the "what if I use..." scenarios for various bullets and powders. After firing, the only sizing that is required is to use the Lee Collet die to reform the neck, then get ready to reload.

So far I have found to different powder combination behind a 175gr Berger VLD that duplicate the GP11 muzzle velocity and almost the same trajectory. I need to place the chronograph at 100 yards to verify the downrange speed difference between those silver bullets and the Bergers. The GP11 projectile was and still is a surpreme long range unit.

The magical chamber pressure number for the K31 with GP11 should be more like 55000psi. This is based on CIP data obtained via the transducer method. Your 45000 is actually the same, pressure-wise, but was obtained via the crusher method. Lots of folks get confused by this and the result is many are loading Krag pressure loads in their K31s and thinking it's a full power load. Stick that number into your Load from a Disk and see what sort of scenarios you come up with.

[excess650]

I'm gettin' in a bit late here, but will relate what I see. My dies are Hornady with the eliptical expander, and marked 7.5x55(purchased 8-10 years ago). My cases were reformed 284 Win, and I never checked length prior to reforming, and were never trimmed. They have been fired numerous times, but only with cast and moderate pressure. Here is what the caliper reveals:

K31 rifle

shoulder diameter fired case: .473"
shoulder diameter sized case: .455"

length fired case, never trimmed: 2.165"- 2.170"
length sized case, never trimmed : 2.175"-2.180"

new Privi case

shoulder diameter: .456"
length : 2.183"

I DO use LeClear dry neck lube on the necks in addition to RCBS case lube on the case bodies. I do FL size, but keep the die from touching shell holder, and visually inspect that the shoulder hasn't been set back.

I was unaware that there were different dimension 7.55x55 chambers, but will now purchase the correct dies despite (not yet) having brass issues.

***update: I see that Hornady and Redding both make dies for the K31. I ordered a set of Redding dies so as to be able to visually differentiate them from my existing Hornady dies.

[spqrzilla]

I've never found that magnitude of brass lengthening in my K31 and no real need for the Redding K31 specific dies myself.