K31 dilemma...

[BoltOperated]

I have recently committed to reloading for my K31's... disgusted with surplus ammo prices and honestly, I want some milder loads for shorter distances. I have loaded a bunch through the years for my pistols - all jacketed. Reloading for rifles will be new to me, on top of that, CB is totally new.

My initial dilemma is that I am finding the K31 seems to be quite picky about the profile of the projectile it digests. I haven't tested this yet... remember, I'm committed but I haven't actually loaded any yet. I plan to in the next few months. Casting my own, however, may be a very far-off endeavor.

This post is yet one more step toward getting prepared to load CB for the K31. I ordered 100 CB from a gentleman on another board, who casts them for his K31. I am hoping they chamber without incident and even shoot well. It will be a while before I test them out. In the mean time, I am here to learn from you all because I intend to load/shoot a lot of CB in the future.

If any of you have any suggestions on which CB are pretty sure bets for the K31, etc., I would love to hear about it. More importantly, where I can get them.

Bill

[35 Whelen]

I have recently committed to reloading for my K31's... disgusted with surplus ammo prices and honestly, I want some milder loads for shorter distances. I have loaded a bunch through the years for my pistols - all jacketed. Reloading for rifles will be new to me, on top of that, CB is totally new.

My initial dilemma is that I am finding the K31 seems to be quite picky about the profile of the projectile it digests. I haven't tested this yet... remember, I'm committed but I haven't actually loaded any yet. I plan to in the next few months. Casting my own, however, may be a very far-off endeavor.

This post is yet one more step toward getting prepared to load CB for the K31. I ordered 100 CB from a gentleman on another board, who casts them for his K31. I am hoping they chamber without incident and even shoot well. It will be a while before I test them out. In the mean time, I am here to learn from you all because I intend to load/shoot a lot of CB in the future.

If any of you have any suggestions on which CB are pretty sure bets for the K31, etc., I would love to hear about it. More importantly, where I can get them.

Bill


You're in for a treat handloading for the K-31. They are just as crazy accurate with handloads as they are with GP-11. I've fired 10 shot, 100 yd. groups out of mine spanning 1.5" or less with with Hornady bulk 150 gr. FMJBT's and ordinary M2 152 gr. pull-down bullets. But you are correct; with their short throat, they're very picky about the bullet used. I lucked into this mould and it's doing really well in my K-31.
http://i60.photobucket.com/albums/h6/308Scout/Cast%20bullets/NEI3081457.jpg
The bullet, cast from wheelweights, weighs 154 grs. +/- and initial bench testing at 50 yds. gave groups ranging from roughly 5/8" to a little over 3/4". What little 100 yd. testing I've done indicates this load is going to shoot around 1 1/2". Two loads I've used with this bullet are 6.5 grs. of Bullseye and 8.0 grs. of Red Dot. These loads yield around 1100 fps and either load will yield TONS of shooting from 1 lb. of powder and a barrel should last indefinitely.
I've been lurking around over at the Cast Bullet Association Forum (http://www.castbulletassoc.org/forum/) and some of those guys do some serious competing with K-31's. They universally recommend either the Lyman 311672 or RCBS 165-SIL moulds. They supposedly fit the K-31 throat and shoot extremely well. I'm waiting for Mid-South to get the Lyman mould back in stock, then I'll order one.
You really need to slug the bore of your K-31. Their groove diameters are normally quite tight. My two measure .3065" and .307". I size the above bullet .309" and it works fine. You'll want a bullet a minimum of .001" over the groove diameter of your barrel.
35W

[B747]

If any of you have any suggestions on which CB are pretty sure bets for the K31, etc., I would love to hear about it. More importantly, where I can get them.

Bill

Bill

The 2 molds that I know about that are sure bets for the K31 are the RCBS-165-Sil and very similer Lyman 311672 sized about 310. The groove diameter is not the primary solution to accuraccy here. I have shot everything sized from 308 to 314 in the K31 --- the real answer is to just fit under the throat diameter by about .0005". Midway , Graf's or Mid-South should all have these in stock.

If you must have a heavier / longer bullet (200 gn+) for wind bucking etc. , then you have two choices --- either fire 15,000 to 20, 000 rounds of some thing similar to the above rounds first or get a taper die that will size the forward driving bands down to fit in the throat.

Wally

[3006guns]

One of the saving graces of this forum is that we are willing to admit to mistakes.....and here's mine.[smilie=1:

I ordered 100 7.5 Swiss brass from Grafs for my K31 and gleefully primed, charged and seated a box of 150 grain spitzers. Now we're cookin'! No more expensive ammo for me! All was well until I tried to chamber the first round and the bolt refused to go into battery. Even though I have handloaded for many years, it never occured to me that I might have to full length resize NEW brass! Had to pull every round apart, size, test in the chamber then reload them. The rifle lived up to its reputation........accuracy was outstanding. Enjoy it!:mrgreen:

[jonk]

Well I've never done much cast reloading for mine. But if you do go jacketed, 36 gr of BLC2 is my go to 'mild' load for accuracy, with a 150 gr bullet. It won't quite shoot MOA as they are cheap surplus M2 bullets but good enough. This load clocks in somewhere around 2100 or 2200 fps if memory serves, so with a good hard alloy and good lube it would probably do fine with gas checked cast.

OTOH cast is all I shoot out of my Swiss 1889 and 1911 with their longer throat. 200 gr Lee 309.

[garandsrus]

I really like the RCBS-165-Sil group buy boolit. It shoots great in the K-31 and has become my standard boolit for the rifle.

John

[Maven]

Bolt Operated, You may want to search our archives for posts (lots) on this subject. In short, the K-31 isn't very choosy about which CB weights & designs it will digest. E.g., it will accept the Lee 113gr. "soupcan"/"wadcutter" and Lyman #311644 (195gr. tapered design) and just about anything in between, IF:

1) you size them to fit your rifle and

2) seat them so that feed through your rifle. This means that the bases of some CB's will be below the neck - shoulder junction, which harms nothing. I know that's heresy, but try it yourself.


Loading data: You can substitute CB starting loads for the .308Win. for the K-31 if need be. Also go to the CASTPICS site (bottom of screen) and look for Articles by Members, specifically "Cast in the K-31."

[PatMarlin]

great thread info here-

[BoltOperated]

35 Whelen,

Those CB look like they would NEVER chamber (because of their profile) according to all the hype I've read so far! I find it comforting that you've had such success with them. Maybe I'll be ble to do this after all!

Thanks to all of you guys for the responses. It helps me greatly in sorting this all out. Like I was saying, it will be a while before I will have a realistic chance at trying casting myself... in the mean time, I will be buying my CB in bulk and having fun.

Two more questions... "Is there a particular CB (and recipe) that any of you have found to be good at 200 yards, or is 200 a task purely for jackets?

also, will my RCBS FL die set be adequate for the K31? I have read a lot about guys who claim that only the Redding set will size brass correctly for the K31. I tend to think it's a bit of embellishment. Besides, I plan to re-fire the brass in the same rifle.

[Ricochet]

Neck size your brass. I use a Lee collet die.

I pretty much stick to jacketed bullets for the K-31 now, as it's tricky to find boolits that will chamber into the short-throated bore without seating ridiculously deep into the case, and use the boolits in the IG 11 and 1896/11. But I've had fair success at 200 yards with the old group buy HBC 200 grain spitzer, seated just a bit deep. Used up to 3.1 cc IMR 7383. (3.4 is way too much, makes for flattened primers, sticky cases, and obturates those HBC spitzers into the rifling halfway up the original long tapered ogive, cast of water quenched wheelweights!)

[Calamity Jake]

For full length sizing you need the Redding or Hornday dies.

[Phil]

I have a Hornady die set and it way oversizes the upper half of the case.

Cheers,

Phil

[chuebner]

I guess I lucked out when I purchased the Lee 160, 180 and 200 gr. SC molds several years back. Each of these molds cast at .298 just forward of the driving band and both my K31's slug out at .297 X .307 so I have a perfect match. These bullets shoot exceptionally well at 100yd. in the 1200-1500 FPS range.

Charlie

[Ricochet]

The 200 grain Lee with that diameter bore rider would be THE perfect K-31 boolit, IMO. The mould I bought casts the bore riders oval, .302 x .304", and it's abusive trying to slam them into the rifling. (My K-31 has .296" bore and .308" groove diameters.) Lee's mould dimensions are pretty variable.

[chuebner]

Lee's mould dimensions are pretty variable.

Man, you have that right. I also have a Lee DC C312-185 that casts one at .313 and one at .3105. That one was either made at 0800 after a holiday weekend or at 1700 before a holiday weekend. Quality control seems non-existent at times. Generally I am a big fan of Lee products but sometimes you have to wonder.

Charlie

[fj3fury]

Has anyone one attempted using the Lyman 31141 in the 7.5 Swiss?

[VintageRifle]

Here is a target I shot at 50 yards with the RCBS 130gr 7.62mm SPL bullet. I sized to .309, and I did get a bit of shaving. Could count for the flyers on the target below. I plan on getting a .308 sizer for these bullets.

One thing is with this bullet and the Lee 312-155-1R sized to .309 is that they shoot 4-6 inches to the right of POA. The K31 that I am using to shoot cast in has had the front sight adjusted to bring impact back to center. It overhangs the front of the site base.

http://vintagerifle.net/images/targets/K31-9grtrailboss50ydsRCBS130gr.jpg

Load was 9gr of trail boss, bullets do not wear gas checks.

[jhrosier]

Has anyone one attempted using the Lyman 31141 in the 7.5 Swiss?

Yep! They worked just fine and gave acceptable accuracy.
I only loaded 40 rounds and shot them at 50 yards.
IIRC, I had to seat them with the top of the gas check just barely inside the neck.
Otherwise it took a pretty good push to close the bolt.

Jack

[35 Whelen]

Has anyone one attempted using the Lyman 31141 in the 7.5 Swiss?

I just checked some of my 311041's and the noses are too big...at least for my K-31. I recently bought a 311672 since that's what everyone seemed to recommend for the K-31. I cast up a few dozen and much to my dismay, the noses of these bullets are too big for my K-31. Very frustrating. I had really high hopes for this mould. I sized some .309" and .310" and went ahead and loaded a few, but they shot worse than the 154 gr. FP I posted about above. Yesterday I tried a few sized .308" and they seemed to do a little better, but I hate to have a bullet telescoped back into the case and that's what happens with the 311672. Honestly, I've about decided the K-31 I shoot the most must have a very good throat as I have to seat most any cast bullet deep.

I really wish we could get a group buy started with a mould designed expressly for the K-31 and it's small-ish bore. I've owned five of them and they all had groove diameters in the .3065" - .307" range and bore diameters around .296" - .297".

35W

[waksupi]

Welcome Fj3fury. I got VERY good accuracy with that bullet in the K31.

[jh45gun]

For full length sizing you need the Redding or Hornday dies.

No you do not Lee dies work just fine and I even questioned this at the Swiss forum asking if I should spend the money on a Redding sizing die and the answer was no not worth the extra money.

[mto7464]

I use the Lyman 165 SW. It drops them at around .310 I size them to .308. I seat them at the crimp groove. I have gotten groups as small as 1.25" at 100 yards at over 2000 FPS with Lino. The 31141 would shoot well and it also would feed well. The 165 SW will feed fine if you cycle the bolt quickly to keep the flat nose from catching on the breech.

[madsenshooter]

Here's a somewhat similar post: http://castboolits.gunloads.com/showthread.php?t=43159 There you can see what Wally means by sizing the front band down to make a boolit fit better, and another boolit that fits the K31 throat well, the Eagan MX3 30AR, similar to other silly wett boolits, but a nose pour mold that I have the cherry for.

[VintageRifle]

This is the 130gr RCBS 7.62mm SPL bullet. 9gr of Trail Boss, 50 yards. 2-10-2009. Group is actually centered over POA. Target was hung at an angle as the target backer was broken.

http://vintagerifle.net/images/targets/K31-50yrdsUCOA9grTB130grSPL.jpg

Target was hung at an angle. Group is actually horizontally centered in target. This is a 5 shot group.

Velocity information follows. These are not the actual velocities of the rounds shot above, but a sample from the same batch.

01. 1315
02. 1245
03. 1258
04. 1254
05. 1259
06. 1323
07. 1289
08. 1275
09. 1286
10. 1254

Average Velocity: 1275.8 fps
Extreme Spread: 45 fps
Standard Deviation: 25.5765 fps

COL: 2.720"

[BoltOperated]

A little update... I wish it was on my progress within the parameters of this thread but unfortunately, no. And, don't laugh TOO hard that this "update" is four years later!

Life took a somewhat unexpected turn, although, in a very familiar direction back in 2009. Since then, I've spent most of my time supporting the effort of our troops in Afghanistan, right alongside them. I hope to get back to "normal" life in the next year and enjoy a somewhat early retirement and spend a lot of time with my favorite firearms and dabble in the art of CB.

The real reason for this post is that I wanted to thank you all for your genuine interest, dedication to a great sport, and willingness to share knowledge that, many times, takes decades to acquire. I hope to be contributing evaluations of range and loadbench experiences soon... until then, I haven't forgotten this place or all its contributors.

-Will

[nitrohuck]

Heya Will,

thread from the dead! If you are still looking for info I may be able to help ya out,

The NOE K-31 Mold is a 5 cavity mold that drops a bullet almost identical in appearance to the RCBS-165-SIL, except that it is advertised as 180gr and comes in 5 cavity instead of RCBS which is 2

For powders that will retain accuracy out to 200yrds, I can say I've had good to mixed results with 2400, and (thanks to 35Whelen) 14.0grs AA#7, which oddly enough is my favorite at the moment.

I have a freshly purchased 1lb canister of Red Dot that I will be trying out... 13.0gr of Red Dot has been recommended to me by multiple people who swear by it.

Someone on this thread posted a photo of a group loaded over Trailboss... it's such an old post that the image is no longer available, but could someone else perhaps chime in if they have used Trailboss in the k31?

For jacketed rounds, I've obtained good results with Reloader 17 powder and the 175 Sierra Matchking, but have just obtained Berger VLD 168's which I hear are superior in the k31, so will have to test those out.

62540625416254462542

[blackbike]

Go to the swiss form, there you will find every thing you will need.
I reform 284win brass and run a 168 match hpbt (J) at about 2700fps with 42gr imr4064.
I have another k31 just for boolits as the front sight need to be off set. For light loads rear sights up to 300 to 500 meeters.
Yea thight throuts, just seat deeper, great shooters.
The swiss shoot ther matches at 300 meeters.

[KCSO]

The K 31 is where the Lee moulds really shine. In most rifles the Lee's cast undersize bullets but they work exceptionallly well in the K31 as most have a tight bore and the short leade works well with the undersize noses on the Lee bullets. The 150 gr fp Lee is outstanding with WW 748 powder up to 1900 fps velocity and at 14-1600 with red Dot or 2400.

[1Shirt]

Agree with KCSO on lee molds with the top of the heap being the 150 gr. I neck size with Lee collet die, and my K-31 likes 2400 loads. Great rifle!
1Shirt!

[HollowPoint]

I posted this photo once before of my 200 yard groups shot with my K31
using the NOE 311365 bullet.

Loaded with 16.8 grains of 2400 and lit by a magnum rifle primer it gives me
a fairly tight group at this distance.

The five shot group at the top of the target should actually be positioned at the
nine-o-clock position if the target were being held correctly.

The five shot shotgun pattern of holes at the bottom left were made with the same gun but,
different charge weights. Hard to explain but, I use the "Optimum Charge-Weight"
method of working up loads.

I was so happy I finally had it dialed in that I asked one of the Range-Masters
to hold the target for me so I could boast of having witnesses to these groups.

Since I had to kind of talk him into posing with my target I was afraid to tell him
he was holding it the wrong way. I didn't want to say anything for fear he'd change
his mind.

I guess he was one of the shy Range-Masters; as apposed to so many of them that
have developed a God-Complex over time. He covered his face with the target.

HollowPoint

[Four Fingers of Death]

I really like the RCBS-165-Sil group buy boolit. It shoots great in the K-31 and has become my standard boolit for the rifle.

John

My friend and his father went into the commercal casting bullet business many moons ago. They were going quiet well doing pistol bullets, but when they tried rifle bullets, they decided that they and the market wern't ready for them and they presented difficulties that did not exist with handgun bullets.

Bottom line is, I ended up with a box of 500 RCBS 165 Sil gas checked bullets. I have tried them in a few things without success, after reading this, they are destined for an appearance in the K31.

[Old Iron Sights]

I found happiness with the Lee 312-155 marketed as the 7.62x39 mould sized to 309.. The profile sits well in the neck and fits the throat. I can get groups under 2" at 100 yd with 18.4 of 2400. I have some loads made up for my other Swiss rifles (1889 and 1911) but waiting for the snow to melt.

I have to turn my lee FL die all the way down to the shell holder or they don't chamber.

[Four Fingers of Death]

I have to turn my lee FL die all the way down to the shell holder or they don't chamber.

That is interesting about the 7.62x39 Lee Mould, my mate has both of these I think, I must borrow them and see how they go. I think the only Lee 30 cal mould I have is the heavy one.

I was led to believe that the Redding die sets are the only ones that were correct for the K31, so I bought those. Talk about a rose amongst the thorns, most of my die sets are Lee and they work well. Perhaps this is what the people that were advising me were talking about.

[Old Iron Sights]

Here's my last grouping. Always one flier in the bunch. Always. I have not yet achieved master caster status yet I guess. I need to shoot this load more and work on getting my bullets consistent and we'll see how it holds up. I don't recall what the fps of this was. Probably was too lazy to take out the chrony that day.

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