bonded core ?

[BT Sniper]

I have noticed that after bonding a core to a jacket it is possible to actually shear the jacket in half part way down the jacket when seating the core in a core seat die after it has been bonded. Obviously I'll just adjust the die so it is not appling as much pressure but I'm wondering if we are actually accomplishing anything when pusing the jacket and now bonded core into a core seat die?

I know we will swell the combo closer to final bullet diameter.

Anyone have any experience with this or thought on this a bit?

BTSniper

[Jailer]

How are you bonding the cores?

I've been thinking about trying this lately but I'll have to find a different way of cleaning the brass so the bond will take. Been thinking of getting a rotary tumbler and some stainless media to clean them up perfect then melting the core in the case while they are annealing.

[BT Sniper]

Corbin actually offers a affordable core bonding product for $7. It is a liquid strong HCL, as in acid. I use a standard dropper you can find at a pharmacy and add one drop to each case. Then drop in core and add heat till core melts, vola! bonded cores. Can be done in same step you use to anneal brass too.

[Hickory]

I used this stuff once to make bonded .224 cal bullets to shoot prairie dogs.
There seemed to be a greater shock value with the bonded bullet but it seemed like a lot of work.

I'd swab the inside of the jacket with a Q-tip and the flux. Then I'd place the jacket with the core in a fixture that would hold 100 in a row. I'd apply heat with a propane torch until the core melted. Then seat the core into the jacket as usual.

http://www.fototime.com/5BDAFD4AE08E18D/medium.jpg (http://www.fototime.com/pictinv/5BDAFD4AE08E18D)

[BT Sniper]

I'll have to post pic of the new bottle I got recently from Corbin. Liquid is clear. Yes q-tip approach can be slow but I found the dropper to be pretty quick and easy though one drop in a 308 jacket vs. a .22 cal jacket is a big differnce.

So anyone split the jacket (horizontal all the way around, not vertiacal) while seating a core after bonding it?

BT

[Jailer]

Corbin actually offers a affordable core bonding product for $7. It is a liquid strong HCL, as in acid. I use a standard dropper you can find at a pharmacy and add one drop to each case. Then drop in core and add heat till core melts, vola! bonded cores. Can be done in same step you use to anneal brass too.

So the stuff is just hydrochloric acid? Do you wait for it to dry then drop the core in? Obviously it's used to etch the inside surface of the jacket. What about treating the jacket, seating the core then melt, cool and point form. A lot of work I know but it would solve the problem of the jacket shearing when you are trying to seat the core.

If it's a one step just form your bullet in a treated jacket melt and run it back through the die after it cools to re form the point in the lead.

[BT Sniper]

I would have to look a bit more at the bottle but for $7 and probably about 3-4 oz it will bond a LOT of cores to jackets.

Don't get me worong here and certainly don't be scared of bonding jackets. It is very easy and I have had great results from 99% of the jackets I have bonded. I was just questioning the need to squish it all together in a core seat die after we allready melted teh core in the jacket.

I hve tried a couple different methods and products. Q-tips and all. What I like and what I have found to work is this core bond stuff with one drop per case followed by dropping core inplace and heating till lead melts. Nothing more is needed! DOn't need to evenly spread the stuff in the case, don't need to wait for it to dry. To much will actually boil over but one drop works great for me. I'll post a pan of the 100 rack tray I made to go in my BBQ that hold the cases while they melt and bond.

This process will work great with the one step dies. Just be sure to where protection. YOu don't want to trap any air below the core. You will make popcon out of the lead as it shoots across your shop.

Only couple of cases I have split was with teh 308 project that I can remember.

BT Sniper

[ANeat]

Bonded or not you can spilt a jacket radially by seating the core too deep/hard.

As you seat the core the jacket will shrink (length) as the diameter expands.

Past a certain point the length will begin to grow again(length) and the jacket starts to stretch and if you keep going it will eventually break

[BT Sniper]

Good to know. I don't think I saw this in any pistol calibers only the rifle jackets so far for me and less then probably 5 in all my time swaging.

[MIBULLETS]

Aneat is right. Seating too hard or with a punch that is a little off of the perfect diameter.

[ANeat]

You can do it every time when the core seat punch is set too deep ;)

There is no bleed hole so something is going to give.....

[MIBULLETS]

Yes, the lead is effectively acting as a pinch trimer for the jacket.

[BT Sniper]

Yes, the lead is effectively acting as a pinch trimer for the jacket.


Makes sence too. The lights lights are coming on. I think I only over had this happen when using a bonded core and thought that may have had somthing to do with it. Guess it is not the fault of the bonded core.

SO.. why do we bother to seat the core after we all ready melted it into the jacket? There isn't that muchempty space left to compress is there? I know we will expand the jacket and core to the diameter of the core seat die and therefore make less work for the point form die but is this the only reason?

Think I ready all about this on Corbins sight I'll have to see if I can find it again.

I mean it seems strange that we are trying to compress a core that is suposidly allready bonded to the jacket.

Well I'm sure I'm putting way to much thought into it.

Just shoot it :guntootsmiley:

Hay!! that's a heck of a slogan [smilie=l:

BT

[MIBULLETS]

The main reason to seat the core is to fill the jacket out to just under final diameter, not just to compress the core. It does make for less work in the point forming die, but it also allows you to put more pressure on the core and jacket than a normal point forming die would. In the CH dies you can still put a fair amount of pressure on the bullet in the final swage or point forming die. I believe there is more precision using 2 steps for atleast rifle bullets in dies using a smaller ejection punch or pin.

[ANeat]

Plus many rifle bullets are not "solid" Many times there is a hollow portion in the nose of the bullet , a "hollow point" ;)

Anyway, the base of the bullet is filled out in the core seating portion and the nose if formed in the point die.

You can play with the weight and fill the nose 100%. In a RF cased 223 for example you can get close to 60gr when filled to the tip, but you can also go much lighter if you like, even with the same external shape; and not have to worry about the point form die needing to generate the pressure to fill the base

[Jailer]

I was thinking about it more for when I start swaging for 450 bushmaster. I'm thinking I want something that stays together at higher velocities better than the 45 ACP bullets I'm making now.

[MIBULLETS]

jailer,

One reason for melting the core before seating is if there is any flux trapped between the core and jacket when it is heated, is because a gas will form and blow the core right out. You do not want to use cores that fit tight in the jacket either for the same reason. The vaporized flux is what cleans and prepares the core and jacket for bonding.

[Jailer]

My plan was to use a heavy .357 mold for cores in the .40 jackets. Prep the jackets and melt the cores in the case when annealing the brass. Seat the cores to expand the base and then point form.

Sound like I am on the right track or am I missing something?

[MIBULLETS]

Nope, sounds like a plan for some good bullets to me. :-)