Lee K31 Dies

[jh45gun]

Just got off the phone with Lee and they said due to the numbers of calls they have gotten on the K31 differences in Chamber over the model 11 they will be coming out with a new set of dies made expecially for the K31. They said they should be out in a few weeks. Jim

[singleshotbuff]

Excellent, thanks for the heads up. I just got a C&R license and this gun is pretty high on my list to be purchased immediately after christmas.

Do you know, if I order these dies, say from Midway, how will I be able to make sure I get the CORRECT newer dies and not old stock?

Thanks

SSB

[Ricochet]

Well, poo! I've just bought both the collet die set and the full length set, plus a Factory Crimp Die, since they don't offer anything but the 2-die sets (and separate FCD) in 7.5 Swiss. Guess I'll have to keep struggling along with these for a while, till I can get a 1911 long rifle to go with these dies and a new set of K-31 dies.

[jh45gun]

You can order direct from the Lee factory if you want to make sure you get the right dies.

[mike in co]

aww..... and then there were those that questioned my statement that only redding had the "correct" die for the k-31.......maybe it had something to do with all the dies being returned for not being the correct die for a k31.....

[Ricochet]

Well, seeing as how all the Swiss issue ammo during the K-31's service life was GP-11 made for the 1911 rifles, and it shot it awfully well, I'm not going to lose any sleep at all over having dies "made for a 1911 chamber." Anyway, I would love to have a long 1911 or 96/11; maybe I'll run into one someday! (For that matter, I'd love to have a nice older 1889 or 1889/96 long rifle. Now I'm set to handload proper ammo for one of those.)

[versifier]

I don't see the problem really. I FL size range brass once, then go with the collet. If the FL sizer brings it back down to around factory dimensions, I can live with that and consider it like a small base die. Does anyone know what the dimensional differences are? I am glad that they're on top of it finally, and might even get a "K31" sizer from them at some point. I suspect I will have to anneal when it's time to set the shoulders back, which could be quite a while with the mild cast loads I'll be running through it.

[jh45gun]

Been having this arguement over on Greybeards site. According to what I have read there the lee and RCBS dies work the shoulder about .020 thousands where the Redding dies only work it 2.5 Thousands since the redding dies are make for the K31 and the other dies for the model 11. My arguement was if it mimics the GP11 loads it cannot be all wrong but then they were made to shoot and throw away the brass in a military situation. Since we reload if you can get dies that fit better that is a plus though if Lee would not have decided to come out with the new die I still would have used my old set instead of paying for the redding dies. Got this off the Swiss Rifle site.

The added clearance immediately aft of the shoulder is an intentional design feature of the K31 chamber, not "slop". Guisan has shown us pictures of an arsenal reamer gauge with the tolerances clearly marked. They include a body diameter just behind the shoulder of 12.0mm to 12.05mm (.473"-.475").



Forward body diameter is not a critical chamber dimension for accuracy. Radial positioning of the cartridge in the chamber is accomplished by the conical fit of the shoulder slope (the critical "headspace" dimension) and the diameter at the breech end of the chamber (12.72mm - 12.77mm, .502"-.503"). The clearance just behind the shoulder allows for more dirt/snow/dents to ensure easy chambering in a combat situation - apparently considered important when the 1911 chamber was redesigned for the K31.

Swiss military chambers were not designed with re-use of fired cartridges in mind, since this was not an element of military use (nor practical with the mercuric priming in use until 1950). Modern handloaders with limited K31 experience sometimes create a lot of fuss about excess body sizing overworking the brass and therefore advocate the Redding dies or even neck-sizing. In actual practice, the neck is worked about the same with all dies (except custom, bushing, or collet designs) and it is the neck that is normally the initial point of failure on work-hardened brass. Shoulder/body cracks are rare, regardless of die dimensions. Both shoulder and neck hardening are easily reversed by a thoughtful annealing program.

Again, Redding makes very good dies that work well for the K31. Their principal advantage is that because they displace less brass during FL sizing, case elongation is minimized and trimming therefore required less frequently than if dies made to 1911 dimensions are used. The disadvantages are strictly economic - higher cost than others and unsuitability for FL sizing cases to be used in the 1911's. I marvel at the willingness of some folks to spend substantially more for dies to enhance case life. Even if the expenditure has the desired effect (probably not), cases are cheap - and so am I.

In handloading for a wide variety of military rifles over the past 50 years, I have encountered only one (a Remington M1903) that was manufactured with "chamber slop" enough to cause problems, although I have seen chambers corroded, abraded, re-reamed, scratched and otherwise abused by users, and some new cartridges that were substantially undersize at base and body. A proficient handloader who is willing to adapt his technique to each situation can nearly always get good case life (and accuracy) with well made and maintained cases - unless he chooses always to load to "maximum" pressure levels beyond the elastic limits of the brass.

[jh45gun]

I do not know for sure but I am going to ask Lee if they will only sell the resizing die if you already have a 7.5x55 set based on the model 11 as I would think the bullet seating die should still work with the new die???

[txpete]

I have 3 rifles chambered for 7.5X55.2 K-31's (43-46) and a custom barrel for my encore.I have been using the "old" lee dies.no problems so far.
on the encore it is a big plus as it has a long throat and after deer season I am going to start on some cast loads for it.
pete

[mike in co]

Been having this arguement over on Greybeards site. According to what I have read there the lee and RCBS dies work the shoulder about .020 thousands where the Redding dies only work it 2.5 Thousands since the redding dies are make for the K31 and the other dies for the model 11. My arguement was if it mimics the GP11 loads it cannot be all wrong but then they were made to shoot and throw away the brass in a military situation. Since we reload if you can get dies that fit better that is a plus though if Lee would not have decided to come out with the new die I still would have used my old set instead of paying for the redding dies. Got this off the Swiss Rifle site.

The added clearance immediately aft of the shoulder is an intentional design feature of the K31 chamber, not "slop". Guisan has shown us pictures of an arsenal reamer gauge with the tolerances clearly marked. They include a body diameter just behind the shoulder of 12.0mm to 12.05mm (.473"-.475").



Forward body diameter is not a critical chamber dimension for accuracy. Radial positioning of the cartridge in the chamber is accomplished by the conical fit of the shoulder slope (the critical "headspace" dimension) and the diameter at the breech end of the chamber (12.72mm - 12.77mm, .502"-.503"). The clearance just behind the shoulder allows for more dirt/snow/dents to ensure easy chambering in a combat situation - apparently considered important when the 1911 chamber was redesigned for the K31.

Swiss military chambers were not designed with re-use of fired cartridges in mind, since this was not an element of military use (nor practical with the mercuric priming in use until 1950). Modern handloaders with limited K31 experience sometimes create a lot of fuss about excess body sizing overworking the brass and therefore advocate the Redding dies or even neck-sizing. In actual practice, the neck is worked about the same with all dies (except custom, bushing, or collet designs) and it is the neck that is normally the initial point of failure on work-hardened brass. Shoulder/body cracks are rare, regardless of die dimensions. Both shoulder and neck hardening are easily reversed by a thoughtful annealing program.

Again, Redding makes very good dies that work well for the K31. Their principal advantage is that because they displace less brass during FL sizing, case elongation is minimized and trimming therefore required less frequently than if dies made to 1911 dimensions are used. The disadvantages are strictly economic - higher cost than others and unsuitability for FL sizing cases to be used in the 1911's. I marvel at the willingness of some folks to spend substantially more for dies to enhance case life. Even if the expenditure has the desired effect (probably not), cases are cheap - and so am I.

In handloading for a wide variety of military rifles over the past 50 years, I have encountered only one (a Remington M1903) that was manufactured with "chamber slop" enough to cause problems, although I have seen chambers corroded, abraded, re-reamed, scratched and otherwise abused by users, and some new cartridges that were substantially undersize at base and body. A proficient handloader who is willing to adapt his technique to each situation can nearly always get good case life (and accuracy) with well made and maintained cases - unless he chooses always to load to "maximum" pressure levels beyond the elastic limits of the brass.

ok here we go AGAIN!
first my brass is not cheap..i'm shooting NORMA brass. 100 pcs of brass cost nearly the same as the rifle! it was the only brass available when i bought the rifle.
second while these are FL dies, i'm only neck sizing.......you cannot neck size only with any of the other dies!....they will size the brass(significantly in some cases) if you try to just neck size! its not for case life..its about accuracy, case life is a side benefit.

i shoot for accuracy period. i'm a firm believer in shooting neck sized cases for accuracy. if the die sizes anything but the neck, i'm inducing an error that i do not want. so yes you can use other dies, but i will not. yes you can use cheaper brass, i dont(well lapua is a little cheaper and i shoot a ton of it). yes you can "reload" with other dies, but with rifles i'm an "ammo crafter" using bench rest techniques. with my loads this rifle shot a 199-11x in a 200yd match.

i never said you could not use other dies. my comments were that if you want the ultimate in accuracy there was only one die that works. i think it is smart to spend money on the correct tools for the job......the difference is defining the job. some of you are talking of "reloading" , i'm not....like i said "ammo crafting".

ya spend yer money. and ya takes yer chances.......

[felix]

Mike, when you really get down to it, you should not size your case at all for the utmost accuracy. ... felix

[jh45gun]

OK just talked to Lee again and they said it is cheaper just to buy the whole set than an individual die so that is what I will do. The guy told me yesterday it would be a few weeks now the lady today said it could be a bit longer then that so I am not sure when they will come out just that they have plans to do so. Maybe a calling campaign to show support will get them moving faster. Lee's number is 1 -262- 673 -3075

[mike in co]

Mike, when you really get down to it, you should not size your case at all for the utmost accuracy. ... felix


felix....do you mean case?? vs just the neck ?? sorry ya got me lost...

for benchrest which is shot at high velocity and high pressures the current method used is bump the shoulder and the base about 0.0005 and the neck with a bushing at 2-4 thou......

in stock guns....milsurplus....i got no way to control the neck portion of the chamber...so one must normally size down some.......just cant get brass that thick!

i understand that some benchrest cast boolit shooters reuse cases without sizing, and seperately seat the boolit in the throat...

is this what you were aluding to ??

mike

[enfieldphile]

Gentlemen,

I have, and use the Redding dies to FL resize cases in my K-31. redding dies are not only very well made dies, they are also works of art.

However, you can use a Lee .308 Winchester Collet die to neck size 7.5 Swiss cases. Works perfect!

Best Regards,

[Ricochet]

So does Lee's 7.5 Swiss collet sizing die.

[Ken O]

I reload for my two K31s, and it takes a lot of force to resize using the Lee dies. I have to trim every time, and take quite a bit off. I thought maybe I had a bad set of dies, but two other guys I shoot with have the same problem. I am going to pick up the collet dies and see what happens.

[0verkill]

Still waiting.

[dhaid-06]

I was excited when I saw the first post in this thread. Then I saw the date...


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