K31 Advice...

[Naga]

I just picked up a pair of K31's, and I will be buying a set of Lee dies sometime in the next couple of days. I would like some advice on molds and powder.

I have been doing some reading on the K31, and based on what I have read, it seems I will need a boolit mold that casts a skinny nose, due to the short throat of the rifle. I have read about several people having success with the Lee 309-xxx style molds, but I am unsure of which one to select. It seems that the longer/heavier ones will stick down past the case neck into the case itself. Is this a problem, or is it a safe bet to choose one of the heavier ones?

In terms of powder, I plan on buying some H-4831 for my M39. Would this powder work well in the K31 as well, or should I purchase a different powder for the K31?

Sorry for the vague questions, but I am being as specific as I really can, given my limited knowledge at this point. Thanks for any help.

[Piedmont]

It looks like you understand the basics. Personally I wouldn' go heavy unless it was a long nose with a very short body, and then it has to fit on the nose, which always seems to be a lot of luck unless you are doing something like an NOE group buy where he will nail it within .001". It is better if the bullet doesn't extend down below the neck. That situation is OK at low pressures but not so good at high pressure.

H 4831 will work, as will a host of other powders.

You might consider dies spec'd for the K31 chamber. If I am remembering right Redding did that with their dies. Maybe someone can confirm or dispute that assertion. I have the Lee dies and they work fine but size the cases a bit too much so they will work in both K31s and the Model 1911s. If I were doing it over I would have bought a set just made for the K31.

[mag44uk]

Piedmont is correct about the Lee/Redding die issue.
I have a K11 and Lee dies and they work fine.
I aquired a set of Redding dies and the resized brass wont fit the gun!
The chambers are slightly different between the K11 and K31 so the Lee dies may be working the brass too much for a K31 chamber.
I use N150 and Vectan TU5000.
There have been some mould group buys on here for K31 specific moulds.
You could have a look in for sales section or put up a wanted ad.
Or check out NOE in vendor sales.
HTH
Tony

[Kraschenbirn]

I use Lee dies for my K31 but, after initial fireforming, necksize only and haven't had any issues with chamber fit or overworked brass. So far as a Lee mould, I've had good results with the Lee 312-155-2R, cast fairly hard, sized to .310, and loaded over either 2400 or AA2015.

Bill

[excess650]

There are K31 dies for K31 chambers, and 7.55x55 dies for all 7.5x55s. The K31 is 7.5x55 but with less body taper, so larger in diameter at the shoulder.

The Lee C309-xxx should work with the exception of the FN which shoot just fine if loaded singly, but won't feed.

The Lyman 311644 is one of the better designs for the K31, and the other I would recommend is the Saeco #315.

Try faster burning powders with cast. I recommend 22gr AA5744 or ~30gr H322.

[jagdkampf]

I have a set of Lee 7.5 swiss dies you can have for postage if you want them. I bought them for the K31 but they oversized the shoulder so much that I started having case head separations after about 3 reloads. I got the Redding 7.5 K31 die and it works much better. I don't use Lee moulds but I really like the RCBS 165gr sillouette bullet. I am getting very good accuracy with it. With 4831 you will be driving the lead bullets a bit fast unless you download it. If so I would use a filler to take up the excess space in the case. I use 4895 in mine and dacron filler and get good groups. Others use 2400 or Trail boss.

Randy

[Maven]

Naga, Use the search function to find lots of information and load suggestions for the K-31.

[NuJudge]

Caution regarding reduced loads with powders any slower than 4895: there is something called Secondary Explosion Effect, or "SEE". which has blown up a number of firearms. It is not well understood, but it does happen with reduced loads of slow powders.

I have used standard loads of 4831 behind a cast bullet, with no ill effects.

[462]

The 7.5 X 55 can be loaded using .308 Winchester information. Buy a Lyman Reloading Handbook...its the best source for cast loads.

[dominicfortune00]

Wonder how the 311365 would do in a K31, being that its' profile looks a lot like a GP11 projectile.

[madsenshooter]

Caution regarding reduced loads with powders any slower than 4895: there is something called Secondary Explosion Effect, or "SEE". which has blown up a number of firearms. It is not well understood, but it does happen with reduced loads of slow powders.

I have used standard loads of 4831 behind a cast bullet, with no ill effects.

One isn't likely to get an SEE using cast boolits. The cause of the effect is the temporary stopage of a jacketed bullet in the throat. This causes a great rise in pressure as the now stopped bullet acts as an obstruction. This has been seen with jacketed bullets but never to my knowledge with cast boolits, they're simply too soft to stop.

CH4D also makes K31 specific dies. They even have a tapered expander so you could make your brass from either .284Win or 6.5x284 if you needed to.

[HollowPoint]

I got in on the group buy involving the 311365 NOE mold.

Loaded with the standard 16 grains of 2400 it shoot extremely well out of my K31. Better than any of the other 30 caliber cast bullets I've shot through it.

It is a long bullet and it does seat deeper into the case than one might like it to but, at these lower pressures it doesn't seem to have the negative effects on accuracy that many have eluded to.

I have yet to shoot this same cast bullet using 308 load data. I may try it just to see what it will do for me.

HollowPoint

[Ole]

Shoot the heck out of it with full power ammo and the throat will open up nicely.

[Txredraider]

I don't cast my own boolits, so I can't give you a good mold number. However, when I was first shooting cast boolits (thanks mostly to lurking around these-here parts), I ordered several varieties of lead projectiles for my military 30s. For some reason I thought a spitzer would be just grand and ordered 100 of them in the 190 grain weight. They shot terribly in everything I loaded them...except the K-31. The short throat of the rifle combined with the spitzer design of that bullet worked like a champ. I post the following link for identification purposes, not advertising.

This is the bullet I have had good luck with: http://www.gardnerscache.com/30_195_spt_g_c.html

[RU shooter]

You maybe be surprised what bullet sizes and styles might fit depending on how much use your rifle has seen of the several I have owned all but two would easily chamber a .311 bullet with a .302 nose and just barely engrave. The other two would chamber well with a .300 nose, So dont rule out certain sizes or designs based on what would or wouldn't work for others slug the rifles throat and see what is actually measures.

Tim

[MtGun44]

Shot a lot thru mine, still no throat.

The factory bullet is two diameter. Smaller ahead of the cannelure, larger aft.

Bill

[Billwnr]

The RCBS 180-SP is another one to consider. I know a few shooters that used it successfully.

[runnin lead]

Using 311299 & 17 gr 2400. For die I am using a Lee 7.5 X 55 neck sizing collet die.
The mandrel in the collet die has been replaced with one from a 303 british die.
With the loiw pressure from this load I have not had any problem chambering without full length resizing.All I shoot out of my K-31 is cast.

[zomby woof]

The Redding dies are the only ones that are just for the K31. That's which ones I bought.
I also bought the NOE K31 mold. I haven't tried it out yet.

[coyotebait]

+1 on the Lee 312-155-2R