K31 swiss rifle and boolits

[ButterNutZ]

I'm flirting with an idea of getting my hands on one of those swiss beauties. Something about the straight bolt pull and the swiss crest on a receiver sparked the interest and the bug has bit me.
I understand that most bores are right around .307 but the lends seem to run tighter than a standard 30cal. My question is would a Lyman 314299 work in that old horse or would I have to get a mold designed for 7.5 Swiss?
Also any of you try a .308 175gr sierra match king in those, if so how did they turn out?

[madsenshooter]

Can't say for sure, but you'll likely find the the nose of the 314299 to be too large for the K31. RCBS 165gr works good in most, I use an Eagan bullet that has a similar profile. I have a very tight bored SIG made rifle. .294" bore, .306 groove. Throats vary, mostly due to some being worn a bit, others have like new barrels. Mine looks a little doggie, marked up birch stock, repair to the butt, warped forearm, but it does shoot good. Haven't tried 175gr bullets, but these fellows have: http://theswissriflesdotcommessageboard.yuku.com/ Since getting rid of my 6x45 AR, the K31 is the most accurate rifle I own.

[Bob S]

Bore diameters in K31's tend to run .296-298. Groove diameters run .307 to .309+. What that means is if you have an old Lyman/Ideal borerider mold with a skinny nose portion that won't shoot worth a damn in US 30 cals, it just might do very nicely in any of the 7.5x55's. I have a 96/11 long rifle that runs .295x.306 bore/groove.

Resp'y,
Bob S.

[ButterNutZ]

Can't say for sure, but you'll likely find the the nose of the 314299 to be too large for the K31. RCBS 165gr works good in most, I use an Eagan bullet that has a similar profile. I have a very tight bored SIG made rifle. .294" bore, .306 groove. Throats vary, mostly due to some being worn a bit, others have like new barrels. Mine looks a little doggie, marked up birch stock, repair to the butt, warped forearm, but it does shoot good. Haven't tried 175gr bullets, but these fellows have: http://theswissriflesdotcommessageboard.yuku.com/ Since getting rid of my 6x45 AR, the K31 is the most accurate rifle I own.

Thanks for the input, I reckon I need to start looking for a mold to go with a swiss girls. Also that forum looks like a wealth of information, thank you sir!

[ButterNutZ]

Bore diameters in K31's tend to run .296-298. Groove diameters run .307 to .309+. What that means is if you have an old Lyman/Ideal borerider mold with a skinny nose portion that won't shoot worth a damn in US 30 cals, it just might do very nicely in any of the 7.5x55's. I have a 96/11 long rifle that runs .295x.306 bore/groove.

Resp'y,
Bob S.

Bob what mold are you running in yours? I have yet to get a rifle, just sort of fidling around for now.

[ukrifleman]

I use the Lee 155gr bullet, mould No.90385, gas checked to .309 in my '55 vintage K31. The bore slugs at .2965/.306
ukrifleman.

[Kraschenbirn]

Barrel of my K-31 (1937 SIG) slugs at .308 groove/.300 bore and, just by dumb luck, I've got a Lee 309-200 mould that drops boolits with a .301 nose. Sized to .310 and loaded over 28.5 gr. H4895, boolit will produce consistent 2" groups off the bench using issue sights. Have also tried the RCBS 30-165-SIL (.302 nose) but found that I had to seat with the gas check below the neck due to the rifle's tight throat.

Bill

[TommyT]

A Lyman 311332 sized to .309 works for me.
87414

[alamogunr]

Not too long ago I bought a mold for K31's from NOE inventory. I just checked and they are out of them. I haven't used it yet so I can't comment on it but others have and a search may find posts on how it performs.

Maybe with enough interest another GB might be started.

[uscra112]

Despite the legends, some K-31s (mine, anyway) are loose enough to take the 311299 just fine. Many won't, and need the NOE boolit or something like. I seriously doubt that any K-31 it would take the 314299. But in any case you cannot go wrong by getting a K-31 to play with. They are rugged and almost invariably very accurate. Scope mounting is a bit of a challenge, but this "scout mount" was fairly easy.

Get the rifle, then figure out what boolit it prefers.

[leadman]

I need to get mine back out to play with. I used to use the RCBS 30-150-SP but the mold has issues now. I have the Lee 180 and 200 gr now and the 150gr on the way. I do know that the Lyman 311041 will work in my gun. I need to load some ammo with the Lee boolits. The 200gr is shooting moa in my old SC 1903a3 sporter.
I put mine in a Boyd's laminated stock and installed an S&K scope mount. Had Jim in Phx mill the top of the mount so the scope sits lower.

[ButterNutZ]

Thanks for the input fellas! I'm looking around town for one and have yet to find it. Might have to hit up the gun shows and such before looking at online vendors. Looks like AIM had some nice ones in stock but sold out in hours! Any of you know a place that has'em in stock?

[alamogunr]

Try Widener's.

http://www.wideners.com/itemview.cfm?dir=700|701|1029

[madsenshooter]

Boyd's makes laminated stocks for the K31? I'll have to check that out, I have a thing for laminates, like this one:

[nitrohuck]

175gr SMK's work great in the K31... that was the first recipe I ever shot a 1" group with at 100yrds (using RL-17 which is the clone of the powder in GP-11 ammo)

I use the NOE K31 mold pretty much exclusively for the K31, although I have had other boolits shoot very well (The lee c309 160/180grs were great but have to be seated deeply)

I mostly use the rifle for pistol powder loads, and the standard 2400/Unique/Red Dot recipes have yielded promising results.

As per suggestion of another member on this forum, I gave 14.0grs of AA#7 a try and it was actually producing some of the best groups of the batch,

ymmv

[Hang Fire]

Despite the legends, some K-31s (mine, anyway) are loose enough to take the 311299 just fine. Many won't, and need the NOE boolit or something like. I seriously doubt that any K-31 it would take the 314299. But in any case you cannot go wrong by getting a K-31 to play with. They are rugged and almost invariably very accurate. Scope mounting is a bit of a challenge, but this "scout mount" was fairly easy.

Get the rifle, then figure out what boolit it prefers.


I have the St. Marie clamp on mount.

http://hstrial-rchambers.homestead.com/P1010652.JPG

[webfoot10]

Look around and try to find the Lyman/Ideal 311414 mold for the 300 Savage. Weights 150 grs. size it to .309 Gascheck it,
over 13 grs imr 4759 powder. Should put them into 1" groups at 100 yds.
webfoot10

[ButterNutZ]

nitrohuck that some great shooting there!
Guys I'm still looking around for one locally and prefer one with a matching numbers. Wideners has a few but they can't guaranty rifle are matching numbers.
Thanks for your input, keep it coming guys!

[tgator]

Try Simpson Ltd. They usually have some in stock.


Tim

[Donor8x56r]

I'm using Lee 155Gr and Lyman 311410 in Model 1911,both sized to 311.

They feed perfect and shoot as well as it can be expected.

[madsenshooter]

Butternutz, when you get one, and if you want a scope mount, go with something like USCRA has shown above, or the St Marie mount. I tried the one from accumount that's on ebay, and had to get a set of windage adjustable rings in order to get on target at 100yds. I could get it on there with a scope that had a lot of windage adjustment, but it used it all.

[ButterNutZ]

Guys just ordered one from AIM. Will give 314299 a shot and see how they do. Look for my report back in few weeks.

madsenshooter thanks for the tip!

[nitrohuck]

Guys just ordered one from AIM. Will give 314299 a shot and see how they do. Look for my report back in few weeks.

madsenshooter thanks for the tip!

just know that you'll most likely have to seat that bullet very deep into the case, not a problem or anything, but just giving you a heads up so you don't get confused as to why the round won't chamber unless the boolit is deeply seated. Often this means the gas check is going below the neck of the case, which does not seem to adversely affect accuracy for most people, but your finished rounds will look a little funny and "nubby" in appearance,

I would very much recommend that NOE K31 boolit mold, sized to .309", things are just a little simpler when the nose fits the bore,

[ButterNutZ]

just know that you'll most likely have to seat that bullet very deep into the case, not a problem or anything, but just giving you a heads up so you don't get confused as to why the round won't chamber unless the boolit is deeply seated. Often this means the gas check is going below the neck of the case, which does not seem to adversely affect accuracy for most people, but your finished rounds will look a little funny and "nubby" in appearance,

I would very much recommend that NOE K31 boolit mold, sized to .309", things are just a little simpler when the nose fits the bore,

Roger that nitrohuck. I might have to buy a small batch of those NOE boolits from someone before buy a mold.

[Idaho Sharpshooter]

The limited amount of cast work I have done with mine, it likes the NOE equivalent of the SAECO 315 tapered bullet just fine. Mine is mostly original, other than the stock having been "sporterized". It does draw the occasional double take with that long, long barrel.

[ButterNutZ]

Well no cast bullets have gone down the barrel of my k31 just yet. However did shoot some loads with 150gr FMJ and IMR8208xbr. Loaded very mild charge, 2,650fps, gave a stellar performance out to 400 yards. No problem ringing 12 in plate at 300 yards and full size IPSC plate at 400.
This is a first swiss rifle that I own and man am I empressed. Only surplus I have is Mosins and boy is it a night and day difference. Dont get me wrong the Mosin hast it's place, but doesn't hold a light next to k31.
Will try to cast up some lyman 314299 and see how swiss girls like those.

[Buzzard II]

Graf and Sons just got in some 7.5x55 Prvi brass. I just ordered some today. Good luck with the K31. Bob

[andrew375]

I use the Lee 150gr. flat nose and the Lee 200 gr. in mine. Both sized .309 for my .3086" barrel.

For jacketed I use the 155 SMK, because I can get them for less than half the price of the 175s; at most distances it shoots to the sights, even though the distances are in yards and the sights meters. But at 900 and 1000 yards I have to put the sight up an extra notch; so sight is on 1100 for 1000 yards.

[Dutchman]

314299 won't work with the K31 but it will work fine in the 1896/11 Schmidt-Rubin
(sized .312"). I ended up using 311332 in the K31.

To experience copper magic try Norma 200 gr Diamond Line moly coated match ammo. Loaded and seated deep for the K31 is shoots MOA in the 96/11.

Dutch

[Shooternz]

Mine shoots great with the Lyman 311332 as well, it's my favorite cast boolit in the .308 I like loading it with 2400 in both calibres. Robert.

[alamogunr]

314299 won't work with the K31 but it will work fine in the 1896/11 Schmidt-Rubin
(sized .312"). I ended up using 311332 in the K31.

Dutch

Does this apply to the 1911 as well as the converted rifle? I haven't slugged mine yet but I have all three sizes of the NOE version of the 311299(+314299 & 316299). I wasn't thinking of the Swiss rifles when I bought those.

[ButterNutZ]

Buzzard II thanks for the heads up, dont have funds for it yet will have to wait until holidays past.

Dutch. You where correct. Tried 314299 sized to .313 and some Unique and no dice. Best group was about 4 inches at 50 yards. But it shoots great with 150 gr FMJ!


andrew375, I picked up that Lee 150 flat nose will give it a try when I cast some up.

Robert I might try that Lyman 311332 but later on. Looks like it would work great in bunch of my 30 cal rifles.

[MtGun44]

40 and a bit (use your loading manual) of IMR 4064 works great under the
Sierra 175 MK. Seat SHORT since these have literally no throat (ball seat).
My memory says 2.860 LOA please make a test cartridge. Too long and it
will misfire. This will shoot 1.5 MOA in my guns. Spend some time on
checking groups with different tension on the action screws, this can make
quite a difference. Loosening the front band (side) screw and see if this
helps accy, too.

Light end of .308 loads works fine for me in the K31, but I would be more
circumspect in the earlier Swiss models.

Prvi Partisan ("nnu" headstamp) is good stuff. It is actually Pi Pi Y -
Cyrillic alphabet characters for Prvi Partisan something, but they look
like lower case n to Americans.

Swiss Products (formerly Saint Marie) clamp on scope mount is superb,
highly recommended, and will hold zero when removed. No mods to gun
at all.

Bill

[ButterNutZ]

Bill that is some great intel! Thanks a bunch. I'll try to tinker with action screws and the sideband to see if I crank down the group size.

[enfield]

are there any of the moulds mentioned that do not put the gas check below the neck when loaded ?

[nitrohuck]

are there any of the moulds mentioned that do not put the gas check below the neck when loaded ?

The NOE K31 mold will

That said, as much as id love my k31 mold (and believe me, I do love it), it surely is not the only mold that produces accurate results in my k31. Some of the Lee molds have actually proven to be very accurate even though they are often considered "cheap" boolits and the gas checks are seated well below the necks.

Fit the boolit nose to the lands, and the k31 will perform amazingly with any .30cal mold

[upnorthwis]

Hope you have better luck with yours that I had with mine. After reading about "Swiss beauties" and "Can't go wrong" Apparently I got the only bad one made. After going thru dozens of choices finally picked one made in 53. Gunsmith didn't have chamber gages but what could go wrong. First shot with factory ammo was a failure to fire. When in did finally go off, it was a hang fire and the primer was blown. We started putting tape on the base of an unfired round to check headspace. End result .030 too deep. Bullet went so deep it would not extract. Also the diameter of the fired brass was .017 larger than unfired. Yes I know they are sold "As is" with no guarantees. I am getting my money back but still will have just under $100 in shipping, transfer fee, and gas for my car. I certainly know how to fireform for an oversize chamber, but what about the next owner.

[AlaskanGuy]

Bummer... I just cant wait to start working on mine.... I just love the action and look of the thing...

I have the lyman 311413 that I wanna try in it, and also on recommendation from the guys at the swiss forum, got the lee Mold C312-155-2R 155 Grain Bullet 7.62x39 on its way... I will post results....

AG

[madsenshooter]

Hope you have better luck with yours that I had with mine. After reading about "Swiss beauties" and "Can't go wrong" Apparently I got the only bad one made. After going thru dozens of choices finally picked one made in 53. Gunsmith didn't have chamber gages but what could go wrong. First shot with factory ammo was a failure to fire. When in did finally go off, it was a hang fire and the primer was blown. We started putting tape on the base of an unfired round to check headspace. End result .030 too deep. Bullet went so deep it would not extract. Also the diameter of the fired brass was .017 larger than unfired. Yes I know they are sold "As is" with no guarantees. I am getting my money back but still will have just under $100 in shipping, transfer fee, and gas for my car. I certainly know how to fireform for an oversize chamber, but what about the next owner.

That's the first headspace problem in the Swiss rifles I've ever heard of. The K31 chamber is larger than the chambers of previous models and the brass does blow out more in the shoulder area, that's normal. Does the serial # of your bolt match the serial # of the receiver?

[upnorthwis]

Don't want to hijack someone else's thread but, I think you may be right. Even though it has all matching serial numbers, the ammo I used, Interarmco, Alexandria, Virginia does not specify 1911 or K-31. I measured the fired brass and compared it to a print in the Sierra edition V. pg. 515 which now that I look more carefully was for a M1911. Shoulder dia. .457 @ 1.753" and top of shoulder dia. .336 @ 1.860" from end. I know where to find the actual K-31 dim's and I will see how they compare. You can understand how a person spends a chunk of money and the gun either doesn't fire or hang fires. My spleen needed to be vented. Thank you in advance.

I signed up on a lot if gun sites. This one is the best.

[madsenshooter]

Yes, but, the length to the datum line of the shoulder should be the same. Only thing that blows out is the diameter. There's no difference in the ammo for the different rifles, is what I'm trying to say. The Swiss just made more allowance in the K31 chamber for dirty ammo. I have to ask, are you sure you didn't get 7.5 French ammo? I don't even know if it would chamber, but I'll check it out.

Guess it will!

http://forums.gunboards.com/showthread.php?67616-7-5-french-7-5-swiss-question

[upnorthwis]

Got 9 rounds from a friend of mine who also bought a K-31. Don't know if he has shot any in his rifle yet. Box has 7.5 Swiss printed on it. Headstamp is G.F.L. 7.5 SVIZZ.

[madsenshooter]

Only thing I can find online about is that it's Fiocchi made. But it could be the ammo is the problem rather than the headspace of the rifle. I'll let you ponder the dimensions.

G.F.L. = Giulio Fiocchi Lecco (Italy).
Svizz = Svizzera = Switzerland.

[upnorthwis]

When I set my Vernier caliper to 1.753" it looks to be exactly at the intersection of the shoulder and body of an unfired round.

[madsenshooter]

Well, then you must've got the rarest of K31s. You must have luck like mine, I once bought a Krag that upon close inspection had a cracked receiver. Could've sent it back, but kept it for parts, mostly the stock.

[waksupi]

If you have a K31 that seems out of spec, I would pour a chamber cast, and be sure no one had ran some other chamber reamer in. My old K11 is a .308, and I know it didn't start out that way.

[Echd]

Bummer... I just cant wait to start working on mine.... I just love the action and look of the thing...

I have the lyman 311413 that I wanna try in it, and also on recommendation from the guys at the swiss forum, got the lee Mold C312-155-2R 155 Grain Bullet 7.62x39 on its way... I will post results....

AG

I thought the same thing when I saw the 311413... I said to myself for some reason this boolit HAS to be accurate in the 7.5!

And I just haven't bothered to try it even though I cast a bunch recently.

[AlaskanGuy]

Well, i am still waiting for dies.. Have the boolits cast.... Just waiting for a way to load them...

AG

[uscra112]

If the O.P. has a fired case, he can measure that to see what his chamber actually is. I've never heard of a K-31 with excess headspace either.

[madsenshooter]

I thought the same thing when I saw the 311413... I said to myself for some reason this boolit HAS to be accurate in the 7.5!

And I just haven't bothered to try it even though I cast a bunch recently.

That 311413 will be accurate, provided you keep it in the velocity range it likes. Best below 1600fps. I've tried harder alloys, heat treating, slower powders, etc. The faster you go, the bigger the groups get. Something about the bullet's balance point I think.

[HollowPoint]

It gives me a chance to show off yet again. My appologies to those members here that have had to view this same pic time and time again. The K31 is a pretty popular and accurate gun so, this won't be the last time a thread like this pops up; or the last time you see the groups shot with my K31.

My Go-To loading has been the NOE Spitzer bullet. It drops from my mold at around 200 grains and is loaded on top of 16.8 grains of 2400 powder and magnum primers in Privi brass that I've had since I bought this rifle several years ago.

I have since modified my NOE mold so that one of the cavities casts Boat-Tails that I can fit my Boat-Tailed Gas-Checks to.

The pic below is one I took a couple of years ago. I have since duplicated this shot spread using the load information I listed above. (not with the Boat-Tails; only with the plain base bullets. I haven't tested the Boat-Tails at 200 yards yet.)

At the top center of the target is my 200 yard group. The range master holding up the target didn't realize he was holding it wrong-side-up. His left hand is actually the top of the target. Mounted on the target stand, I was aiming at the upper left bullseye. My shots were hitting about 8-9 inches low at 200 hundred yards before adjusting the scope so they hit about 6 inches low. The shotgun pattern of shots at the bottom of the target are with my old Enfield. With the Enfield I hadn't yet come close to finding a pet load.

Also; I have a scope mounted to my K31. There's no way I could have shot a group like that with iron sights. My scope is an old BSA 8x32 I've had since BSA first came out with them.

HollowPoint

[madsenshooter]

If the O.P. has a fired case, he can measure that to see what his chamber actually is. I've never heard of a K-31 with excess headspace either.

He mentioned the fact that the bullet sticks in the throat, maybe he has a tight SIG barrel like mine. We know what happens when the serial # on the bolt isn't straight up, failure to fire, or a hangfire as the final bolt rotation takes energy from the striker. And, with a bullet hard into the throat, increased pressure. Maybe enough to blow the primer. Interrupter lug should be checked too. http://theswissriflesdotcommessageboard.yuku.com/topic/7021/K31-accidentSAFETY-CHECKS

http://www.swissrifles.com/sr/rheadrick/k31bolt.html

[madsenshooter]

HollowPoint, tell the guy covering up the name tag didn't work, I'd know that face anywhere! Target face that is.

[upnorthwis]

Madsenshooter, I may not have had the bolt serial number straight up when it misfired on that first attempt. Also noticed that rounds that I chambered but did not fire were .085 shorter than unchambered rounds due to being forced hard into throat and pushing the bullet farther into the case. Three out of the five shots I took had blown primers.

uscra112. Yes, fired cases measured OK. I think the tape method of measuring head space gave me a false reading.

The other thing I learned is if I've got a gun problem to start my own topic.

Thank you all

[madsenshooter]

We enjoy helping no matter where we find the threads, right Phil? I just don't read the ones that aren't pertinent to the solution(s) I'm after. That's a lie, I read them all. Check out the links I left and if you want, start a new thread to let us know the final solution you found. Now you can get down to enjoying the rifle, mine is the most accurate milsurp I have, jacketed or cast.

[SanPedroShooter]

I had a member here send me a good number different casts to try out in my Swiss. The NOE wont chamber properly unless I seat with the gas check past the neck.

The mold that seems to 'fit' the best is the Lee/ Harris AK mold. 312155 something like that.

Can someone explain why you would size to .311 if your bore slugged at .308?

[uscra112]

Size the boolit to the THROAT, not the bore. A boolit that is smaller than the throat suffers gas cutting as it transitions from the case to the bore. Perhaps less so in the K-31 which typically has a very short throat, but nonetheless.....

[SanPedroShooter]

So I was reading on the LBT site about a throat slug kits. Could I just drill a hole in a piece of wood, pour some lead into it and get a correctly sized slug?

Is there a starting guess for common throat sizes? Like should a .30 cal throat fall in a certain range? I looked into a couple different 30/31 cal milsurps I own, and I can see the smooth part of the chamber before the rifling starts.

Does the casing neck and bullet both share the throat? Just trying to understand what I am looking at.

[madsenshooter]

To make what Veral refers to as a throat slug, I sacrifice an old empty case, fill it with some hard alloy. Start a softer slug into the throat just far enough that you can chamber the filled to the mouth case. Then I take a rod and hammer the slug against that filled cartridge, expanding the slug out into the throat. That's what Veral wants if he's going to make you a custom mold that'll fit the throat, he calls it an impact slug. For my .306 groove diameter K31 I size .308. My cases are already fireformed, the ogive is already into the throat and the bullet is going to seal any gases as soon as the primer and burning powder gases starts it moving. I've not seen any difference in accuracy between .308 and .310 in my K31, but there are a lot of variables involved. I generally use a harder alloy than what most would be using, for example.

[uscra112]

What he said. A Cerrosafe cast of the throat is even better, but you have to actually have some Cerrosafe.

For a rod I'm now using a cut-off stainless Hoppe's cleaning rod, with a machined-down brass jag that just barely fits down the bore as a "nosepiece". And a brass guide at the muzzle, which is a drilled-out .222 case!