Heat treating/quenching

[Marlin Junky]

I was wondering if anyone has ever tried to quench in ice water only up to the crimp groove in order to retain a soft boolit nose. I'm going to shoot a few through the .358 (with near a case full of DP-74) after fully immersing half the boolits in the experiment in ice water and the other half of the boolits up to about the crimp groove... unless it's already been done and failed miserably.

I'm starting with BHN 12 metal (clip-on WW seasoned with solder). Any input?

MJ

[VTDW]

IMHO you would have better luck by quenching and then heating just the nose. When you quench to the crimp groove you will also be hardening the nose as well, just not as much. By immersing the boolit in water up to the crimp groove you can then just heat the nose for the result you want. It takes just a bit of practice but is easy and works.

Dave

[randyrat]

VTDW I need to do this someday. I plan on loading some 30 cal for plinking and hunting. Next november i want to be ready for that big buck. Give us a little more insight on this if you will. How hot do you heat the bullet nose to? THANKS

[VTDW]

I use a propane torch to heat em up. You will learn to count to a certain number before the nose melts.:mrgreen: As in heating aluminum, you can get a seat of your pants feel for just before the metal melts or starts to slump. Just play with a few and give them the old hammer test:-D to see how the nose does or squeeze em in a vise.

[Marlin Junky]

I use a propane torch to heat em up. You will learn to count to a certain number before the nose melts.:mrgreen: As in heating aluminum, you can get a seat of your pants feel for just before the metal melts or starts to slump. Just play with a few and give them the old hammer test:-D to see how the nose does or squeeze em in a vise.

VTDW,

I thought about doing it your way (actually I first heard about this method from Paco Kelly) and it may work better than my idea but if I can get the partial quench method to work satisfactorily, it'll definitely be faster. Maybe I'll just quench to the first third from the GC.

MJ

[Ricochet]

Gotta have tough fingers to hold onto 'em while they're quenching. :mrgreen:

[leftiye]

M.J. You might also try (if the base first in water hardens the whole boolit too much) just setting the boolits upright on a heat sink like a thick piece of aluminum. After all, just hardening even the very bottom land should be sufficient. This may well be an alternative to the other method of annealing the noses! Thanks for the idea.

[Marlin Junky]

M.J. You might also try (if the base first in water hardens the whole boolit too much) just setting the boolits upright on a heat sink like a thick piece of aluminum. After all, just hardening even the very bottom land should be sufficient. This may well be an alternative to the other method of annealing the noses! Thanks for the idea.

Lefiye,

If you experiment with the process let me know your results. I found a lil' rectangular wire basket at Wally World (I think it was in the kitchen section) that I use for a heat treating rack and I'll set it into about 1/2" of ice water after HT'g at 450F tonight. Late next week I'll shoot the partially submerged boolits along side some that were quenched normally by submerging completely in ice water. I'll be driving them all 2200 to 2300 fps with DP-74 in a .358 Win to see if there's any difference in group size. All boolits tested will start from the same casting session and will be BHN 12 (WW metal with a bit of solder).

MJ

[grumpy one]

MJ, among the many problems that may arise is the issue of how the ice-water heats during the quench. You might consider using a deep pan of ice water with a hollow-center stand in it, and lowering your basket of bullets onto the stand, so water can circulate better. It isn't a great solution since the hot water tends to rise to the surface, but the boiling action might stir it up somewhat. You need a fair mass of water unless you just put a very few bullets in the basket.

Obviously you can experiment with how much of the bullet you immerse, to get the hardened section to extend the desired distance up the bullet. Looks to me as if the key will be how fast you can quench the back of the bullets. Unless you restrict yourself to half a dozen bullets at a time, I think only the outermost ones are likely to quench.

[BruceB]

At the risk of being called a "one-note piano-player", I will again state that casting bullets with PURE LEAD noses is infinitely more-controllable than partial-hardening or partial-softening, or any other way of trying to make "expanding" cast bullets.

Pure lead is a KNOWN quantity. It will NOT harden or soften, no matter what we do with the rest of the bullet.

It's also a KNOWN QUANTITY in its sterling performance on game, having served us admirably in hunting bullets for generations. A cast bullet with a suitably-tough shank area, coupled with an INTEGRAL pure-lead nose of whatever size we desire, is the best of all available worlds where cast hunting bullets are concerned.

Simply by changing the proportion of the bullet which is pure lead, we can tailor the bullet for quicker (or slower) expansion, and for deeper (or shallower) penetration by reducing or increasing the potential expanded diameter of the fired bullet through our varying of the percentage of bullet weight which is pure lead.

To mess about with half-measures of softening uncertain parts of the bullet to uncertain degrees (in MY not-so-humble opinion) is to miss the boat with regard to controllable production of KNOWN-quality bullets.

I reckon that should get the idea across....?

[Marlin Junky]

I've got to heat treat anyway because BHN 12 isn't strong enough to handle the pressure of 45 grains of DP-74 in a .358 case so I thought I'd try something a little different just to see how the boolits react to not being completely immersed in ice water. I dipped 13 of them tonight, after being baked for an hour in a 450F oven, into ice water up to the crimp groove and kept them standing in the water until the meplats were cool to the touch... which didn't take much more than a few seconds.

Waste of time, perhaps; but, when I get around to casting boolits purely for hunting big game, the first thing I'm going to attempt is paper patching.

MJ

[Lloyd Smale]

got to agree with bruce. Its tough enough just to get consistant hardness just water dropping bullets and i would think it would be a nightmare to try to consistantly get two part tempers. A much better solution would be a two part bullet. I cast them for my 4570 with lynotype bases and pure noses and with a little practice and a good rythmm you can get perfect bullets that way. Reject rate is about 50 percent if your not looking for perfection but the rejects make good practice bullets anyway. I cast the rcbs 405 round flat that way and the ballistic cast 540wfngc. Both bullets are gas checked designs so if i guy didnt have lynotype you could probably get away with ww for the bases. I use a pistol case to dip the nose. Ive found that a 38 special works great for the 540 and a 40 sw works perfectly for the 405. Just get your mold good and hot. Dipper in the nose count to 5 and pour the base. When the stars are aligned i get perfect bullets and the only way you can tell there two part bullets is the nose will be shinnier.
At the risk of being called a "one-note piano-player", I will again state that casting bullets with PURE LEAD noses is infinitely more-controllable than partial-hardening or partial-softening, or any other way of trying to make "expanding" cast bullets.

Pure lead is a KNOWN quantity. It will NOT harden or soften, no matter what we do with the rest of the bullet.

It's also a KNOWN QUANTITY in its sterling performance on game, having served us admirably in hunting bullets for generations. A cast bullet with a suitably-tough shank area, coupled with an INTEGRAL pure-lead nose of whatever size we desire, is the best of all available worlds where cast hunting bullets are concerned.

Simply by changing the proportion of the bullet which is pure lead, we can tailor the bullet for quicker (or slower) expansion, and for deeper (or shallower) penetration by reducing or increasing the potential expanded diameter of the fired bullet through our varying of the percentage of bullet weight which is pure lead.

To mess about with half-measures of softening uncertain parts of the bullet to uncertain degrees (in MY not-so-humble opinion) is to miss the boat with regard to controllable production of KNOWN-quality bullets.

I reckon that should get the idea across....?

[Marlin Junky]

got to agree with bruce. Its tough enough just to get consistant hardness just water dropping bullets and i would think it would be a nightmare to try to consistantly get two part tempers.

I'm not water dropping from a mold while casting which is a poor method of hardening WW metal if boolit to boolit BHN consistency is one's goal. If the method I've described above works suitably for 13 boolits (compared to complete submerging) I'm going to eventually try up to 100 boolits. It's much easier to fill a pan with a layer of water and place it in the freezer for about 1.5 hrs than how I was water quenching which involved making enough ice to cool a gallon bucket of water before quenching.

MJ

[Ricochet]

I water drop because it's the most convenient way to cast without getting bullets deformed from knocking into one another as they drop out of the mould. I can cast hundreds of 'em without having to rearrange piles of hot bullets on a towel. I can sort out the problematic ones later, though they're more easily seen when not underwater. For consistent hardness, I heat treat 'em all later. The ice is unnecessary. Sometimes I anneal 'em all in a batch, when I want soft bullets.

[rhead]

I do the same as Ricochet. I water drop everything just for the cushioning effect of the water. Then I either aneal or heat treat to get a consistant hardness.

M J I can't think of why it wouldn't work If you have a problem with the bullets falling over while they are far enough apart to not interfere with each other in the quenching step try adding another layer of hardware cloth with a big enough mesh to keep them upright and evenly spaced. I have not seen a difference with tap water and ice water. Anti freeze will give a slightly softer bullet that will sometimes shoot better. Keep us posted on the results. If it works or not we will have still gained knowledge.

Good luck!!!!

[Marlin Junky]

The hardness tests on the meplats of partially quenched (to the crimp groove) vs. fully immersed boolits reveal a BHN difference of approx. 4.5. I haven't checked the trailing driving band yet and will probably just shoot 'em all tomorrow to see if there's any difference in group size. The loads will be warm... 45 grains of DP-74 in the .358 Winchester. I was hoping for more of a difference but the meplat of the partially quenched boolits was just about half way in hardness between air cooled and fully quenched. Next time I may try quenching to the lube groove and testing the hardness both on the trailing band and on the meplat about 1 to 2 weeks after HT'ing.

MJ

P.S. I saved two rounds from yesterday's range session and pulled the boolits to test hardness on the meplat and trailing bands. There was a difference of about 4 to 5 BHN on the partially quenched boolit. It might be interesting to try this again with a 50/50 clip-on/stick-on WW mixture.