Making My Own 8mm Jacketed Bullets

[j0e_bl0ggs (deceased)]

OK need a solidworks drawing of the plastic tip, bruv is ok with printing 'a couple hundred'!

[gitano]

I can be just as hard-headed as you can. :)

Complexity in reality is 1 extra dimension with the advantage that the punch stem will be a larger ø therefore will be stronger. "1 extra dimension" is MORE complex.
The length of the punch that bears upon the lead core can be say 1/8 -1/4 long so will not decrease flexibility of use with this jacket - remembering that you will not be able to use this punch with a 'standard' jacket. I can concede that point.
The real advantage is applying the swage pressure concentrically and having support guiding the punch to avoid bending the stem, in all probability it will reduce the possibility of die or punch damage. There isn't a issue with concentricity as the 'system' forces concentricity regardless of punch diameter. The punch will stay in the center of the jacket if it touches the jacket. I can handle the 0.0005" of eccentricity caused by the 0.001" of 'slop' between the jacket wall and the punch. There will be exactly the same concentricity issue with the side of the die wall as there is with the side of the jacket. I'd rather have the 'slop' with the die wall.

I truly believe "bending" due to applying pressure won't be an issue when the punch is made from "real" steel, and probably hardened as well. (12L14 will NOT harden.)

The 'damage' issue comes from 1) hitting the side of the inside of the die with a punch that barely fits in it, and more likely, 2) capturing a bit of "schmutz" between the punch and die wall. I didn't say it WOULD cause damage, I said it would increase the likelihood of damage. I'll stick with that assertion.

When setting these dies you have to sneak up on your finished dimensions regardless of the punch shapes being used - if you don't, well it's only a 2 year wait from Corbin for a replacement! All the more reason to not increase the likelihood of damaging one.

I'll genuinely reconsider a 'stepped' punch end.

The more I think about it, the more I 'like' the "Kamm" back. It has fabrication implications, (easier on dies AND extraction), as well as external ballistic ones. The one POSSIBLE 'negative' is complete fill-out of the jacket in the core swaging die. That is "non-negotiable". I don't THINK that will be an issue with the "Kamm" back as the OD of this prototype was 0.323'. Which reminds me, I didn't mic it, I only used my dial calibers. I need to mic it. I'm pertty sure I would prefer that  the finished diameter be 0.3235" instead of 0.3225".

I need to find out what the diameter of the "ski binding plug" is. However, I agree with j0e_bl0ggs that the 'spring-back' is likely to be a 'deal killer' without some form of heat applied. I think injection molding, (self or contracted out), and 3D printing are the methods to focus on to start with. Also asking Hornady and Nosler if they will sell me some of theirs.

j0e, can your brother use a DWG file as long as it's a rendered 3d?

Paul

PS - Ski Binding plugs are nominal 5mm (0.197") in diameter. That keeps it 'in the mix'.

Paul

[j0e_bl0ggs (deceased)]

That radius base grows on ya!

[gitano]

I sent the following to Nosler and Hornady:

Gentlemen,

I have been a satisfied customer of yours for quite a while now. (I'm 61 so you can make your own guess on exactly how long.) While you do make some 8mm bullets that I use, you do not make a bullet of the type I want to use in the 8mm rifles I make for myself. Since I 1) make my own ammunition, and 2) make my own firearms, I'm sure you can imagine that I am inclined to 'have things my way' if at all possible. When manufacturers won't make a product I want, I do my best to make it myself. So... I have acquired all the equipment and materials necessary to fabricate my own jacketed bullets.

I have a bullet design that I like - nothing fancy by any means - and have produced a couple of prototypes with which I am very pleased. The bullet can be both an 'open tipped' hollow point or have a 'plastic tip'. It is simply a light-weight (117-grains), heavy-jacketed (wall thickness of 0.035"), open-tipped hollow point similar in design to Speer's 130-grain .30 caliber HP. It goes very fast out of a wildcat 8x376 Steyr.

It's the plastic tip I would like to ask you about.

For the prototypes of the plastic-tipped version, I have purchased tips made by Cutting Edge Bullets. https://cuttingedgebullets.com/cgi-bin/commerce.cgi?preadd=action&key=TALON_M

As you can see, they are VERY proud of their tips. Which brings me to my question of you: Would you be willing to sell me some of your plastic bullet tips?

Maybe it is relevant to say that I am not now, nor do I ever intend to be a manufacturer of bullets for sale. I will not compete with Nosler. My interest is solely for personal use. I buy your reloading components and don't resell them as loaded ammunition. I make my own rifles and do not sell the guns I make. I would greatly appreciate a supply of plastic tips for my "handloaded" bullets that I didn't have to pay more than 50 cents a piece for.

Thank you for your consideration,
Paul Skvorc

The ONLY hope I have is that the worst thing they can say is "No".

Paul

[gitano]

The above bullet mics at 0.3233"

Paul

[gitano]

Just for comparison's sake. 7mm Speer 115-grain HP, .30 cal Speer 130-grain HP, 8mm 117-grain ANVB.



Paul

[gitano]

So I thought I'd measure the length of the bearing surface of the 8mm ANVB instead of guessing about it.

Here's the total length of the bullet - 1.068" (Subtract exactly 1.000" from reading to account for gauge.


Here's the length of the bullet NOT considering the part of the "Kamm" back that is smaller than the "caliber" diameter of 0.312". (0.312" is the land diameter of one of my Remmington 700 8x57s.)  0.9975". That makes the "Kamm" back 0.0705" long.


Here is the length of the bearing surface at "caliber" diameter (0.312") back from the tip but INCLUDING the "Kamm" back. 0.350".


So... To find the actual length of the bullet that is greater than the land diameter of the bore, all I have to do is subtract the "Kamm" back length (KBL) from the Total length (TL), and then subtract that value from the length of the bullet at a point back from the tip where the diameter is 0.312". (I'll call it Nose Length (NL)).

So the equation looks like this:

Bearing length = NL - (TL - KBL)

Numerically:

BL = 0.350 - (1.068 - 0.9975) = 0.2795"

Since a "caliber" is 0.323", 0.2795" represents ~87% of a caliber.

While that measure applies to the length of the bullet that is actually touching the lands, it is NOT the measurement to be used for actual reloading/bullet seating. There is some more 'cyphering' necessary to get seating depth/cartridge overall length (COL) values for QuickLoad.

COL is determined from bullet length, seating depth, and case length. COL does not 'care' about the "Kamm" back (or any kind of boat tail). Therefore, the amount of bullet AVAILABLE to seat into a case is simply the NL plus the KBL, or

0.350 + 0.0705 = 0.4205".

That in turn is 130% of one caliber. (0.4205/.0.323=1.301)

The length of the bullet's nose (ogive) that is larger than 0.312" in diameter (land diameter) is the total length minus the bearing length plus the "Kamm" back.

1.068 - (0.350 + 0.0705) = 0.6475"

So the "nose" is ~half again as long as the bearing surface part of the bullet. Generally speaking, that's not a great characteristic for gyroscpic stability since that puts the center of mass well behind the center of form. However, 0.4" of the "nose" is actually the plastic tip.  I has almost "no" mass relative to the mass of the bullet that is larger than 0.312". So the "real" length of the bullet that is ahead of the land diameter is TL minus the length of the tip or

1.068 - 0.4 = 0.668"

Now compare the "non-nose" length of the bullet - 0.4205" with the length of the bullet discounting the plastic tip (because it has "no" mass relative to the total bullet mass), and the part of the nose ahead of 0.312 is only

0.668 - (0.350 + 0.0705) = 0.2475

Now, the proportion of the bullet's length that is "real" nose is;

0.2475/0.668 = ~37%. That, speaking in the context of gyroscopic stability, is WAY "better" than 150%.

All of this number-crunching has two purposes:
1) To get numbers to use IN QuickLoad so I can get good numbers OUT of QuickLoad,
2) to get precise measurements for cutting a new 8mm Steyr Short Throat (8mm SST), chamber, and
3) to illustrate WHY these "stubby" bullets - the Speer 115-grain 7mm HP and 130-grain .30 caliber HP - shoot so straight.

I expect an 8mm bullet that has a similar nose-length-to-total-length ratio as the Speer bullets, (that shoot so straight), to shoot "straight" also. (The "short nose" means that the center of mass is close to the center of form). AND... because it is nearly a cylinder in form, I expect it to "hit" like a "hammer".

Armed with the precise dimensions of the bullet, I can cut the leade on the chamber of the 8mm SST to "fit" the 8mm ANVB 'perfectly'. For example:

If, after I do the barrel timing calculations in QuickLoad, I find that I want the seating depth of the 8mm ANVB to be one caliber (0.323"), that leaves exactly 0.0975" of bullet that is "caliber" (.323) in diameter ahead of the mouth of the case. Since I am not interested in loading bullets "on the lands", I need the throat to be at LEAST 0.098" long. In fact, I prefer the "jump" the bullet has to make to reach the lands to be AT LEAST 0.030". I prefer it to be in the 0.050" to 0.150" range. If I were to load a bullet to one caliber deep, and have a MINIMUM 'jump' of 0.030" to the lands, the throat would need to be

0.0975 + 0.030 = 0.1275" long.

If on the other hand, I want to cut the throat for that circumstance where I might want the bullet loaded "out" and the 'jump' to be 0.150", the leade would have to be cut to a length of

0.107" (1/3rd of .323) + 0.150 = 0.257"

We'll have to see what QuickLoad says about seating depth and barrel timing.

Paul
 

[j0e_bl0ggs (deceased)]

ANVB _ PFC...

[gitano]

The above tips were made by j0e-bl0gg's brother on his 3-D printer. Took less than an hour to 'print'. (I think it's an $80,000 printer). Pretty darn cool!

Here's a closer shot:


I like the translucent look.

Paul

[gitano]

So... Finally got the blasted press squared away and commenced the process oflearning what there was to getting the 'set-up' right. I figured I would just start simple, and make some "regular" "spitzer" bullets, and maybe some closed-tip bullets. No need to work on the plastic-tipped set-up yet.

I cut the appropriate length of lead wire, (final weight - 124.5 g), inserted it in the jacket, (no need to swage core at this point as I was only interested in forming issues, not weight), lubed jacket, put jacket and core in die and rotated the arm.

Hmmm.

Kinda tough sledding. I looked at the bullet. The core was well-seated, but the 'butt' was still very round.

I put it back in the die and leaned on it a bit more. A little movement, but not much.

I reinserted it in the die and leaned on it as much as I dared. Essentially no change.

Hmmm....

I thought maybe the place to 'flatten' the butt might be in the point-forming die, (PFD), so I removed the core-seating die, (CSD) and installed the PFD in the press.

I lubed the jacket-with-seated-core and "leaned" on it as hard as I dared.

Hmmm.... Not much of a point, AND no butt flattening.

I lubed it again, and leaned on it again. Broke my bench:stare: - 3" glu-lam - Not much change in the "point".

"OK" I think, it's not 'closing' up because the lead is so close to the mouth of the jacket that it can't. Fine. I'll use less lead.

I remove the PFD, install the CSD, and repeat the core swaging with less lead, (final weight 89 g). Still no flat butt out of CSD.

Removed the CSD, installed the PFD, and 'leaned on it'. Same result as last time.

Repeated process with NO lead - just an empty jacket.

NO CHANGE (essentially) in the "point".

Hmmm....

It APPEARS that there is a reason why the "factory" bullet manufacturers don't use   jackets with wall thicknesses of 0.035". I am pretty sure that is the reason why I can't get the tips any more closed than you see in the following pictures.



and


When I look at the bullets that the manufacturer of these jackets make, I note that the diameter of the jacket of their bullets right where the exposed lead tip starts, is just about the diameter I am seeing on these bullets I am making.

So, what does that mean for my bullet-making?

First, it means I have to get/make a stronger bench.

Second, I think it will be essentially "impossible" to make "closed-tip" hollow-point bullets with these jackets. There's no heartburn there for me. I'm not interested in such.

Third, I don't think I am going to be able to square the base without making a die to perform that operation specifically. At the moment, I'm not interested.

Fourth, I am going to concentrate on fin-tuning the process of making the ANVB style bullet with the long, pointed, plastic tips. I LIKED that bullet form before I realized this issue with the thick-walled jackets, so this is pretty much all the incentive I needed to FOCUS on the ANVB.

More when there is more to report.

Paul

[j0e_bl0ggs (deceased)]

Woah there son...

I thought maybe the place to 'flatten' the butt might be in the  point-forming die, (PFD), so I removed the core-seating die, (CSD) and  installed the PFD in the press.
I lubed the jacket-with-seated-core and "leaned" on it as hard as I dared.
Hmmm.... Not much of a point, AND no butt flattening.
I lubed it again, and leaned on it again. Broke my bench:stare: - 3" glu-lam - Not much change in the "point".

This is how you break stuff, dies punches or bench!

There should be no 'lean on it' going on.
After consideration - and you will not like this - you need an extra punch for your core seat die to square the base of the jacket before seating the lead core.

I would suggest that the gitanogorilla is reigned in a little - it is not the time to jettison the analytical mind... easy there son!

And you are not going to like this but it is worth measuring up your dies and punches with the jackets just to check that 'working distances' are correct and a boo boo has not been made.
Oh just a thought does the press 'cam over' at  the bottom of the levers stroke?

Can you set up your dies to make a lead only bullet just to check operation?

There were sample bullets with the die set if I recall, can you take pics of these too?

Most importantly is that you have not broken the dies or got a jacket / bullet stuck in the point form die  - yet...  

TANBF

This Aint No Boiled Frog...:D

[gitano]

Those comments indicate far too many assumptions. I don't "break things" by strong-arming them. Things break sometimes because they are not up to the task given to them, which is the case with my bench. I knew it when I attached the grossly over-built press.

Unfortunately, there is no 'cam over' with this press. The handle hits the floor before that point is even close. Even if the table were high enough so that the 3-foot handle wouldn't hit the floor, it would require almost 180 degrees of rotation to achieve 'cam-over'.

I set the dies up so that the face of the capture nut on the FPH meets exactly the face of the die. With the FPH screwed to a specific depth, the action, and range, of the press is correctly set.

With respect to the bullet that was provided with the die, I would point out that it was to demonstrate the correct configuration of the die, not the press. Also, the jackets of the samples Corbin supplied are about 0.012" in thickness; almost one third of the thickness of mine (0.035").  You can't cram copper into a space smaller that it will fit, unless you have some serious mechanical advantage. Closing the tip on a jacket with 0.012" walls is considerably easier than closing the tip on one with 0.035" walls. I will run a solid lead billet through the pointing die.

Paul

[gitano]

Here is a picture of a swaged solid, pure lead bullet formed in the point forming die. Adjacent is the finished bullet Corbin provided. (I'm not going to take it out of its sealed bag for this exercise.) If you look closely, you can see that the jacketed bullet's tip is actually larger than the lead bullet's tip, even though I pushed the lead billet slightly into the extraction tube.



Paul

[j0e_bl0ggs (deceased)]

Those comments indicate far too many assumptions. I don't "break things" by strong-arming them. Things break sometimes because they are not up to the task given to them, which is the case with my bench. I knew it when I attached the grossly over-built press.

Unfortunately, there is no 'cam over' with this press. The handle hits the floor before that point is even close. Even if the table were high enough so that the 3-foot handle wouldn't hit the floor, it would require almost 180 degrees of rotation to achieve 'cam-over'.

I set the dies up so that the face of the capture nut on the FPH meets exactly the face of the die. With the FPH screwed to a specific depth, the action, and range, of the press is correctly set.

With respect to the bullet that was provided with the die, I would point out that it was to demonstrate the correct configuration of the die, not the press. Also, the jackets of the samples Corbin supplied are about 0.012" in thickness; almost one third of the thickness of mine (0.035").  You can't cram copper into a space smaller that it will fit, unless you have some serious mechanical advantage. Closing the tip on a jacket with 0.012" walls is considerably easier than closing the tip on one with 0.035" walls. I will run a solid lead billet through the pointing die.

Paul

Cam over is the part of the stroke where the 'work' is done.
Again you misunderstand, not worried about the "correct configuration of the die"
I am more concerned regarding how the dies have been set up in your press.
The handle hitting the floor before the stroke is finished is not good.
35 thou jacket will close up - no problem.

[gitano]

By the way, the wall thickness at the mouth of the hollow point of the bullets shown in post #70 is 0.040". They have thickened at least 0.005" after having been closed only about 0.055" per side .

Paul