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Swaging tool design

4144 Views 15 Replies 6 Participants Last post by  talon
As a teenager back in the early 1960's I had a Corbin swaging set for .357mag. Long gone, traded for something else I wanted.

Now that I'm a little further along in life, I'm interested in building (I have a lathe and mill) tooling that can be used with standard presses using 7/8-14 dies.

Have any of y'all considered swaging bullets (from cast bullets or cast cylinders)? I think it would be interesting to refine the fit of a cast bullet to the throat by carefully designed dies.

What dies are out there (in design or for sale) that work on standard presses?

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One of the concerns in cast bullet shooting is obturation (sealing) of the bullet in the throat of the barrrel. With jacketd bullets the typical arrangement is that of a straight taper is met by the curvature of the ogive giving a circular line of contact around the bullet to the bore. But with lead bullets there is more to conisder, because of the softness of the lead. Some have found that by carefully matching the taper of the throat with the taper or form of the bullet gives greater accuracy.

What I am looking for is knowledge or experience in creating this match between bullet and bore. Casting a bullet requires a mould of a particular shape. It is a major undertaking to make or modify the cavity to make a change since it is irreversable.

Could then, a press be used to swage all or part of a cast bullet to modify the shape or diameter of the nose of the cast bullet, to modify the shape or diameter of the bullet where it seals, or to modify the major diameter (as in sizing/lubricating) of the cast bullet?

Perhaps this could be done with a modified nose punch for one of the common lube/sizers?

Going in a different direction, Lee has come up with a neck sizing tool that (I have only read of these) compresses from the sides to get the neck of the brass to a specific diameter. This leads to the question of could not a similar technique (radial instead of axial) compression by swaging - as a technique used with existing forms of bullets?
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Donna - I will admit to having a different perspective on things. As I remember from my experience in the early 60's with swaging, even with the 1/2 jacket I would get leading in the .357Mag. I ASSUME (classic definition) that this was because swaging required soft lead. Further the costs of the 1/2 jackets put the cost right up there with purchased bullets.

So to me the issue is one of function - can swaged bullets be driven as fast as hard-cast well-lubricated cast bullets (1800-2800fps) without leading? Coupled with this is the cost of each bullet. This has brought me to the concept of using the cast bullet as the starting point - low cost per bullet, made on relatively low cost equipment commonly available.

I will admit that making one's own jacketed bullets, not just 1/2 jacket has some intregue as well. It means controlling to the nearest 1/10,000 not just 1/1,000 of an inch to get the accuracy that the jaceted bullet is capable of.

I guess being an engineer has taught me to question and improve the process, not just the product. And since I have a mill and a lathe (purchased specifically to make moulds) I guess I can play a little.

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Lead Pot - interesting process - sounds like not that much more than casting/lube-sizing.

Am I right in thinking that it would take a die that would eject the bullet (much the same as the lube-sizer) but with a special nose punch that would fit the die precisely? Would the nose punch be vented?

This looks like a machinist's project that would be fairly straightforward - with flexibility in making changes in nose punch form to slightly change nose style - perhaps moderate hollow pointing or hollow basing as well.

I would think aslo that it would take more than a C or O press due to the need to eject the bullet.

What do you use - what brand/source?
Ahhh, the wonders of living in the conufser age (technical term). Y'all have given me/us a wide perspective in such a short period of time.

I guess my next step is to do more reading and then narrow my focus initially on some phase of casting/swaging that is fundamental.

That means I'll start with wadcutters and focus on getting weight and dimensional stability good and work into matching up with the throat. Your comments are invited.

LP - you mentioned using a baseguard on the base of the bullet. Is this something like a short 1/2jacket, gas check or more like the Harvey protex washer?

What metal? Copper?

Steve - I looked at the dies you referred to on ebay and I'm familiar with the older Corbin dies (from experience as a teenager) and the Corbin websites. I think I'm going to take this a small step at a time - by building simple functional dies and trying these things one at at time. I guess my objective is not to just make the bullets, but to try out other ideas.

talon -

Baseguard - seems like a cool idea - are they put in convex or concave side up (next to the bullet)?

Agree with you on the value of someone elses product. It is a fundamental of engineering design - if someone else makes it, BUY it - don't make it yourself, as it's much cheaper, better designed and quality control procedures are in place.

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