PDA

View Full Version : use .005" wide saw blade to do the six petal HST cut on jacketed and cast bullets



Oldfeller
02-15-2024, 09:50 PM
Yes, indeed there are .005" thick very very thin saw blades available now-a-days.

Use the clean link just below

https://www.amazon.com/vdp/0da84c820f2846fc9215ed0bb66178ed?ref=dp_vse_ibvc0

A little consideration and practice has resulted in some ogive deep .005" wide HST like cuts on a jacketed slug for a 350 Legend.

https://www.amazon.com/dp/B07RTBPL62?psc=1&ref=ppx_yo2ov_dt_b_product_details

https://www.amazon.com/dp/B07GVNS8F1?psc=1&ref=ppx_yo2ov_dt_b_product_details


Future thoughts lead me towards trying to mount this blade on a variable speed oscillating multi-tool to make the cuts much easier to accomplish in bulk.

Cutting jacket and lead by hand is surprising fast at 2 min. per cut, with the resulting swarf being a lead and oil paste similar to cream cheese in consistency. An osculating tool mounted cutter could get the job done in 10-20 seconds per cut.

Some fixturing could easily remove half of this "fumble to get it right" time.

(yes, you do have to oil the blade to keep it from leading up on you).

323487


Please note the incredibly fine cut is barely visible in this picture .... I had to blacken the cuts so yo could see them at all.

Note that the .005" wide cut also tends to close up on itself after the lead and jacket tension relaxes for a few minutes.

You do need a small cone form on the tip of the bullet to start the petals to moving to "open the bullet up".

Oldfeller
02-16-2024, 09:42 AM
Also note you can easily put these same cuts into a cast lead bullet, with powder coat or greased formats working equally well.

Out of a rifle you will tend to lose the plain "as cast and cut" lead petals with the resulting rifle speed "explosive expansion", but with more reasonable lower velocities common to simple greased lead bullets making the trick operate more understandably.

If you understand and like HST type expansion, you might value knowing about this trick.

Barry54
02-16-2024, 10:09 AM
I definitely like the concept!. I knew an old fella that said that they were so poor back in the day, he used to cut the tips off of full metal jacket ammunition and then take his pocket knife and carve an X shape on the tip for hunting ammunition.

I would be concerned about keeping everything concentric and balanced.

Oldfeller
02-16-2024, 10:31 AM
The bullets in question have a six slot skive pattern left over from the original Zero bullet processing, so it is easy to keep the razor saw cut pattern on center. Note that the original Zero bullet as shipped isn't considered to be expanding by the mgf. even though they never state that plainly in the advertising materials.

Furthermore, discussions on some of the other development theads that I put forward on milling slots in the face of the bullet to create impact jet effects brought out that any extreme out of balance conditions would take over 25 feet of bullet travel to significantly affect impact or dispersion patterns of defensive pistol distance type shooting.

This is relatively "completely balanced" as a bullet modification goes. It is in a symmetrical pattern about the bullet center of rotation and the amount of lead removed is very insignificant weight wise. And the weight removal is balanced and symmetrical as well.

The individual slits are very quick to add once you get your fixtured oscillating cutter all set up. 5-10 seconds per slot is the going rate once you get the bullet holder "v" block all centered and and completely set up.

It is easier to slot a completed round as the assembed cartridge gives you something to hold on to.

popper
02-16-2024, 11:17 AM
So you make 'dum-dum' loads?

Oldfeller
02-16-2024, 02:29 PM
Punch Federal HST into your browser and look at the expansion pictures. The expansion form looks like this for moderate 1,000 to 1,200 fps speeds, but the results get all buggered up on the petals breaking off by some higher rifle type bullet speeds.

At the very top end rifle speeds, you see something like this sort of performance from a 150 grain hollow point bullet ..... the front end of the bullet explodes into lead dust and fragments and the solid short shank bores on deeper, tumbling as it goes.

At 2,700 fps speeds no petal cut plain lead slug is going to do perfectly ...... those supported by a jacket will do better but once again not perfectly. This trick will work better at 950 to 1,000 to of impact speed which means any rifle load out of a 350 Legend will work jest fine when it arrives at the critter's fur.

whisler
02-16-2024, 08:25 PM
Great idea, thanks for the post.

20:1
02-17-2024, 07:21 PM
So you make 'dum-dum' loads?

What was old is new again.

nanuk
02-19-2024, 10:48 AM
Winchester made the "Black Talon" brand bullets for awhile, the handgun ones expanded like those with the exception, the jacket left a little hook on the end
I believe it was that "hook" that coined the term "talon" AND why the Alt-Left was so opposed to them... they were just TOO SCARY.

as if getting shot by a standard hollowpoint was less lethal and hurt less then one that killed much quicker.....

Oldfeller
02-21-2024, 09:48 PM
OK, I have fiddled some more with the idea by powering the blade with a 2 amp Warrior oscillating cutter from Harbor Freight. Driving the little saw blade with a power tool actually works too well --- it verges on being uncontrollable even at the lowest setting the tool has.

Having achieved more "speed" that was uncontrollable, now I am working on slowing it down and fixturing it to make it easy to do and a lot safer.

Slowing down brushed motors like the little 2 amp Warrior hand tool is the avowed purpose of my lab grade Staco Variable Transformer. To preserve the electronics installed in the tool's handle I first turned the unit up all the way and then I run it in a range from 30 to 50 volts using the large lab grade variable transformer. (This is an old lab grade sliding coil variable transformer that does a real non-overheating 0-120 volt output power off a single rotation of a large calibrated knob.

I can readily control the little saw blade at the start of the cut using about 25-30 volts ...... but once I have the cut established from skive to skive I can ramp the motor up to 50 volts to make the cut depth finish out in less than 10 seconds.

Control of the assembled round comes from a glued up t-shaped piece of 1 by 4" that is through drilled with a 3/8" drill bit. My assembled cases start to bind on their case taper about half way up the 3/8 hole so I can rotate the case to get the blade all aligned with the bullet nose skive pattern, then I push the case in to get it to bind up and stop rotating. Then the entire glued up rig is slid forward to allow the blade to cut down to full depth.

So, I turn the power off to align the blade in the next set of skives, roll the power up to deepen the cut then I turn the power off and pull back on the glued up rig to release the bullet from the fully embedded blade. Finger pressure is enough to free the case taper in the drilled pine hole and then I rotate the fully assembled round to the next set of skives and repeat the process.

Needless to say, you are working close in with a razor blade mounted power tool, so extreme "reloading level" attention to detail and extreme caution levels are required.

And yes, I did cut myself in a minor fashion early on while doing it free hand --- so some early fixturing was developed accordingly.


:roll: