Now that I have all of the pieces actually in hand, it's time to start a new thread on the fabrication of my own 8mm (.323 caliber) jacketed bullets.

I still have to do some modifications to the press and make a floating punch holder, but the important 'thing' is that I have the press, I have the dies, I have 5000 jackets, and I have quarter inch pure lead wire. "You" can find some history on this endeavor here:  http://thehunterslife.com/forums/showthread.php?t=12747&page=1

I'll post pictures of the press when I get it reassembled after reboring and rethreading the ram so that it will hold the beefier bullet swaging dies.

Here are some dimensions on the jackets:
Average weight = 42.13 grains
Outside diameter = 0.323"
Inside diameter = 0.253"
Length = 0.71" (The pictures below will provide important information about the nature of this measurement.)
Wall thickness = 0.035"

Here is a picture of the jackets as I received them. On the left is a .416 bullet from the same manufacturer that made the jackets. On the right are two jackets; one "round" end up, the other open end up.



Looking at the bullets I have received from the company that sold me the jackets, it is clear that the rounded part of these jackets is the back end of the bullet. Using the place on the jacket where it goes from rounded to straight, I get a length of 0.595". Subtracting another 0.035" from that for the thickness of the bottom of the jacket when the bullet is in its final form, I get a "core cavity" dimension of 0.560" x 0.253", (length x diameter). Armed with that information, I can calculate the length of lead I must have to achieve a specific weight bullet.

Here's where using the metric system would be VERY helpful, but since the firearms/hunting community uses inches and grains, I'll do the 'messy' conversions. Lead has a density of 11.34 grams per cubic centimeter at room temperature. Converting that to grains per cubic inch, I get 2,876 grains per cubic inch for the density of pure lead at room temperature.

A cylinder with the length of 0.560" and diameter of 0.253" has a volume of 0.02815 cubic inches. Multiplying the volume of the "core cavity" (0.02815 cubic inches) times the density of pure lead (2876 grains per cubic inch) yields the weight of the core of a bullet made with this jacket IF it was filled to the top of the jacket with pure lead. That weight is 80.97 grains. Add to that the 42.13 grains of the jacket, and we get a finished weight of 123.09 grains. I asked the jacket maker to make the jacket lengths for a 125 to 130-grain finished bullet weight. I think they did a good job.

I am quite certain that the jacket is going to lengthen a bit when I form the ogive. That, (in combination with the fact that actual chemically pure lead is pretty difficult to come by so the true density of what I have on hand is probably slightly less than theoretical), means I should be able to produce an "open tip", hollow pointed bullet somewhere in the 120 to 130 grain range. If I want to make a "spitzer" with exposed lead tip, it will probably finish in the 130 to 140 grain range.

There are a couple of observations that I have made with respect to the relative size of these jackets and those of the 7mm and .308 versions seen in the other thread. (If you use the link above to go to that thread, look at post #58.) The length of the finished 7mm bullet is 0.93". The length of the .308 bullet is 0.84". The finished length of this 8mm jacket/bullet is calculated to be something slightly longer than 0.6". Since the ogive is a fundamental and immutable characteristic of the dies, I don't have much leeway when it comes to the nature of the ogive of my bullets. The curvature of the ogive on my dies is 8 times the radius of the caliber (8R). In other words, the radius of curvature of the nose of bullets made in my dies is 8 times 0.1615" or 1.292", (a circle with a diameter of 2.584".)

I may be able to 'fiddle' with the ogive a LITTLE bit by adjusting the distance into the die that I push the bullet. In other words, if I push the jacket-with-core into the die "all the way", I'll end up with a "closed tip" hollow point. (See other thread for explanation of differences between "closed tip" and "open tip".) If I don't hardly push it in at all, I end up with a "cylinder" shaped bullet. Somewhere in between "all the way" and "hardly at all" is where I have a LITTLE 'room to move'.

The significance of this is the length of the bullet's BEARING SURFACE. The bearing surface lengths of the Hornady, 8mm, 125 grain closed-tip HP AND their exposed lead spitzer of the same weight, are fairly short - 0.285" (0.88 calibers) and 0.338" (1.05 calibers) respectively.  The bearing surface length of the Speer 115 grain 7mm open-tip HP, (the bullet design upon which I am basing my 8mm design), is 0.465" (1.64 calibers). The length of the bearing surface of Speer's 130 grain, .308 open-tip HP (the same bullet design as the 7mm caliber), is 0.453" (1.47 calibers). I'm guessing that the bearing surface of my finished bullet will be pretty close to 1 caliber. We'll see.

IF these calculations turn out to be correct - and I will be surprised if they aren't close - this is just the weight of bullets I wanted to make.

Next step is "reality"...

Paul

Good stuff Paul.

I noticed the jacket thickness you have measured at 0.035". How does that compare with Speer .308 130gn HP and their 7mm 115gn HP? If the jacket thickness is the same you should expect similar performance on game with the same size HP.

A guy here in OZ was making projectiles for the .303 British. He was annealing the jackets first. He claimed that this would make for a softer jacket and therefore expand better at lower velocities. Shooters that used these bullets claimed they worked too. No hard evidence for it though.

Standing by for the next installment.....

Now this looks very interesting, too bad no one has told you that you can't make your own jacketed bullets but have to buy them from the factory:nana:

Quotetoo bad no one has told you that you can't make your own jacketed bullets but have to buy them from the factory

Who said they didn't! People practically lined up to say "you can't do that" (without spending $2000+ on hardware to do it).

22hornet - The .035" wall thickness is actually pretty thick as factory bullets go. The jacket on most bullets is in the 0.015" neighborhood, as are the jackets on the 7mm and .308 Speer HPs. Of course bullets like Accubonds and other "specialty" bullets have fairly complex, non-uniform wall profiles.

As for annealing: That's PROBABLY not necessary with these jackets. MOST bullet jackets are made of so-called "guilding". "Guilding" is a copper alloy not too different from bronze. These jackets are pure "electrical grade" copper. (Or so I'm told.) As such they are pretty soft as they sit. Of course even pure copper work-hardens, so we will see what happens after seating the core and point-forming.

The thicker wall and the "dead soft" copper are why I like this manufacturer's bullets.  Barnes bullets - the ORIGINAL bullets made before Fred Barnes sold the company - were made with pure copper jackets. One of the reasons manufacturers shifted to "guilding" was the increased fouling of pure copper that showed up when bullets started being launched at higher and higher velocities. I may have that problem with these bullets out of the 8mm SLT at 3200+ f/s muzzle velocities. I'm quite certain there will be no fouling at subsonic velocities, and I'm hoping it won't be too bad in the upper 2000s.

It is my opinion that the combination of the thicker wall AND the soft copper will enhance the terminal performance of this bullet. Since the Speer 7mm and .308 bullets are labeled "varmint" bullets, and I KNOW they are big-game 'hammers', I'm hoping the terminal performance with the thicker wall and soft jacket material will make this hollow point something other than a "varmint" bullet.

Have you seen these https://cuttingedgebullets.com/cgi-bin/commerce.cgi?preadd=action&key=TALON_M

Paul

PS - Turns out that there is a Cutting Edge Bullet distributor about 15 miles from my house. I just ordered 25 of those "Talon Tips" from him. We shall see what we shall see.

Wow, price of those 'tips'.....
Definitely going to have to make the injection moulder...

Yup, AND they insist on using UPS for shipping, so 25 tips that weigh maybe an ounce, cost $15 to ship to AK via UPS. USPS would be $4.80 Priority. However, when I spoke with the distributer here, he said he'd split the shipping fee with me for "some samples of your bullets". I told him emphatically that I was NOT in the bullet-making BUSINESS. He said he understood, but would still make the offer, so I took him up on it.

Honestly, I have my doubts that these tips will work WELL in my bullets. However, once I can get them in my hands, I expect to get some ideas about how to accomplish the same thing for my bullets. In the end, I suspect it will be as simple as spec'ing a point design and contracting a company to make "a million of them" for me. If I can get 1000 as a minimum batch at a price of say less than 10 cents a piece, I'd be happy with that.

I want to use these Cutting Edge tips to help me see what MY bullets need for specifying a tip to a small parts manufacturing company. Because of the length of the jacket and the extension of the tip into the jacket, I think one of my bullets with a tip will weigh even less than 120 grains. Lighter is OK with me.

Have to make some bullets first...

Paul

Paul, you know that you can always have stuff shipped to me and I'll forward it USPS flat shipping or whatever is cheapest.

Funny you should mention that... :D

For those that don't already know, A-Square Bullet manufacturers went out of business. All of their stuff was auctioned off about a month ago. I got a number (10) of "test" barrels (Krieger and Lothar Walther). Cost for the barrels - $214. Cost for shipping BY UPS $274. I was going to ask if I could have them UPS'd to you and you could USPS the to me. I'll give you a call.

Paul

Interesting jacket, will have to pursue the tube jacket maker now!

EXACTLY what I was thinking!

I've been looking at 5/16ths "refrigeration" tubing. At ~0.75" per round-bottomed jacket (meaning actual length of tubing would be slightly longer), I'm thinking I could get at least 12 jackets per foot of tubing. At ~$1/ft in 50-ft rolls, that's 600 jackets for $50, or 12 cents per jacket. A bit cheaper than 28 cents per jacket.

Wall thickness of THIS ASTM 68 tubing is 0.032". OD is nominal 0.3125", ID is 0.2485". All those are about "8mm" bullet dimension. HOWEVER, I suspect that "drawing DOWN" 3/8ths might be easier/better than swaging UP 5/16ths. Therefore, the "better" choice MIGHT be 3/8ths (0.375 OD) tubing. When drawn down, it would probably have a wall thickness of ~0.035". By the way, wall thicknesses up to 0.065" are available in ASTM 68.

Paul

Paul, Think that you could have some in 150gr to 200gr to me in time to work up a load to hunt deer with this fall?

Not with these jackets. They'd be more than half exposed lead. The 200s at least. HOWEVER, I would like you to try the light ones once I get some made. They might convert you to a light-for-caliber fan.

Paul

Quote from: gitano;123621EXACTLY what I was thinking!

I've been looking at 5/16ths "refrigeration" tubing. At ~0.75" per round-bottomed jacket (meaning actual length of tubing would be slightly longer), I'm thinking I could get at least 12 jackets per foot of tubing. At ~$1/ft in 50-ft rolls, that's 600 jackets for $50, or 12 cents per jacket. A bit cheaper than 28 cents per jacket.

Wall thickness of THIS ASTM 68 tubing is 0.032". OD is nominal 0.3125", ID is 0.2485". All those are about "8mm" bullet dimension. HOWEVER, I suspect that "drawing DOWN" is easier/better than swaging UP. Therefore, the "better" choice MIGHT be 3/8ths (0.375 OD) tubing. When drawn down, it would probably have a wall thickness of ~0.035". By the way, wall thicknesses up to 0.065" are available in ASTM 68.

Paul

The 10.5 thou 'swage up' is close enough at a guess - saves making a drawing die...

Paul, if you send them I'll shoot them and see what I can do. My K98 likes the 185gr Core Locks but I'll try lighter stuff.

The ram has been bored and threaded and reinstalled in the press. The floating punch holder (hereafter FPH) has turned into a bit of a challenge. (I guess the 'challenges' never end 'til you die.) Nobody in The Valley has any 1-inch bolts with 12 pitch needed for the lock-nut.  There are plenty of 1-8s and 1-14s, but no 1-12s. Ditto for the 1.5-in 12 pitch All-thread for the die body. Plenty of 1.5-8 and 1.5-14. No 1.5-12. Gee I wonder why Corbin would choose an "odd" thread pitch for his dies? (It's a rhetorical question.)

It's not too big of a deal. I can find the 1-12 bolts in Anchorage or on the web if necessary and I can simply thread the outside of the die body myself. It's just that a bolt and some Allthread would have greatly decreased the time I will have to wait to start making bullets.

Paul