Here are my first handloads for the Swiss K-31 carbine. They're using HBC bullets cast from wheelweights, dropped from the mould into water and aged to harden them, and dipped in molten Johnson's Paste Wax for lubrication. Prior to the waxing, they were bright silver. Slippery little boogers to pull out of the box by the bullets to stand up for the photo!



Time to go shoot 'em now, so I can load 'em up again!

I've had pretty good success with these from the .300 Weatherby at 2000 FPS with Johnson's Paste Wax and White Lightning bicycle chain lube, propelled by IMR 7383. I'm using the 7383 in these loads, too, and expect they'll be around the 2K speed mark.

1995 FPS. No leading. 2 1/2" groups at 100 yards. (Not bad for me.)

I am impressed... Everything I ever read about spitzer-shaped cast bullets was that they wouldn't group due to the bullets' nose(s) becoming elastic in flight, causing them to wobble.

Good looking rounds, and pretty darned good shooting, from where I stand.

Well, I don't see any reason for them not to fly the same as a jacketed bullet of similar shape, IF they get started straight. That's the hard part, where the long unsupported nose can easily tip and bend if it's not hard enough to resist the pressure of firing and sets back or slumps. These are very hard. The peak pressure's modest with this large charge of slow burning powder, similar in rate to 4350 but below book starting charge weights. The bullets are sized to be a tight fit in the chamber neck and throat, so they don't get a chance to wobble and tip before starting down the bore. They're getting off to a good straight start. And in the K-31, they also happen to be starting right against the origin of the lands. I've been shooting them in my .300 Weatherby with similarly good success at ~2000 FPS. There they're about 3/8" away from the lands, but are a snug fit in the smooth freebore section ahead of the rifling, and the pressure is even lower with a somewhat larger charge of 7383 giving about the same velocity from a case with half again as much capacity. Guiding them into the bore straight is the key. They shouldn't be sized to fit the grooves, but the throat, IMO. In both the K-31 and the Weatherby, the .311" bullets are a tight fit in the necks of unsized fired cases. Can't push 'em in by hand. With lubed lead alloy bullets, that doesn't concern me at all with regard to bullet release on firing. The loaded rounds will chamber and extract easily.

Hmmmmm. I've wondered about this design in this particular cartridge. What with the short throat and long ogive, it just might work.

Have you tried any other lube? Any other powder charge? I'll be watching for developments as I have 3 of these 1 Cavity moulds.

In this rifle, this is all I've tried. In the .300 Weatherby I've also used them tumble lubed with White Lightning bicycle chain lube, which works well. 7383 is the only powder I've tried with them. I've had this mould for 2 years or so, but just started working with it recently. And I just got the K-31.

I think there was an earlier version of the HBC in 8mm, which I wish I had.

Where did you get the mold? Website would be nice. Thanks.

This was a Group Buy from Lee several years ago. Designed by Aladin as a "High Ballistic Coefficient" (HBC) boolit suited for long distance work.

You might be able to shake one loose from a poster here, who knows.

It was available as a custom order about two years ago. One place you could've placed an order for it then was right here. Aladdin is the handle of the guy who designed it and honchoed the deal. Only way to get one right now is to find someone with one they'd sell. Mine's not for sale, I like it.

I did find a load that shot it very badly yesterday. 45 grains of 7383 under this bullet in the K-31 is too much. Gave sticky extraction. The velocities were extremely consistent in the mid 2100s, but the bullets were all over the place. I couldn't get them on paper consistently at 100 yards. At 50, I got about a 1 foot group. The high pressure was causing uneven slumping of the long unsupported nose. A bystander told me he could see a spiral smoke trail tracking the bullets' flight for about 25 yards. (Hot smoking wax.) The fact that it was obviously spiral tells me the bullets were unstable as they left the muzzle. Got to keep the pressures lower to get good results, aside from the fact that that load was a little too hot for the rifle.

But even with this overpressure load at 2150 FPS, the Johnson's Paste Wax kept the bore nice and clean, with the barest discernible trace of lead in the corners of the grooves. Made a nice lube star on the muzzle crown.

quote:

Originally posted by rainman1882:
Where did you get the mold? Website would be nice. Thanks.

I did the CAD work on it. If you want an AutoCAD file of the drawings I can email it to you.

A few people have asked about it. If enough were interested, and someone would honcho the group buy (I'm not interested enough to do that), Lee would make another batch. Perhaps Midsouth would do a deal like they've done with some of the other Cast Boolits customs, keeping "replica" moulds available for sale.