Finally made a swaging die that doesn't stink...very much

[Coxworkshop]

Turns out die making is hard! who would have thought. I think I finally have a die that makes half decent slugs. Definitely not going to give any of the really slugs out there a run for their money but a big win for me. I can get about a 1.5" group at 50yrds with my airarms Krait. Baby steps.

Couple of my takeaways:

• The diameter of the slug mattered more than the profile or general shape
• Deeper hollow points tended to do better
• Taking the time to harden the dies properly was well worth the time as it made them much easier to polish. (will likely help with longevity as well)
• The overflow extrusion hole should be no bigger than 3/32 to create enough pressure to fully fill out your die.
• Making a slug that shoots well for everyone is probably not possible. Barrel bore, and the tune need to be factored in when designing a die/slug.
• If you use swaging lube its worth the time to washing your slugs after.

I'm not experienced enough to state any of the above with confidence but they tend to be true with my limited experience.



These are all the dies that I made before I got one that makes half decent slugs

 

[GeneT]

Good work! Are you hardening the dies yourself, or sending them out? Details of material and hardening process if you're doing it yourself...

I think the best solution (except for big bores, where it may not matter) is to make a slightly over-sized slug and let the customer size it to their barrel. Of course that means the customer needs a lubrisizer or sizing die, etc.

I've considered Moly-coating slugs if I ever get around to making them. Have you tried it?

GsT

 

[Coxworkshop]

Good work! Are you hardening the dies yourself, or sending them out? Details of material and hardening process if you're doing it yourself...

I think the best solution (except for big bores, where it may not matter) is to make a slightly over-sized slug and let the customer size it to their barrel. Of course that means the customer needs a lubrisizer or sizing die, etc.

I've considered Moly-coating slugs if I ever get around to making them. Have you tried it?

GsT

Yeah hardening myself. I'm a parttime knifemaker so luckily I've already got the setup and background for hardening. I'm using A2 steel and I fully harden it to 60+ hrc and then temper WAY back to 50. I do my final machining hard. Leaves a really nice finish.

That's a great idea. Make a standard oversized slug and then just resize it. I hadn't really thought about that. But its pretty common practice with powder burners, no reason it wouldn't work just as well for airguns. Good thinking!

I've not looked into the Moly-coating. Its for swaging?

 

[sb327]

Excellent work! I don’t think most realize how difficult it can be to make a swage die set that actually works. I have made several and I am still learning.

What do you use to machine yours?

Dave

 

[GeneT]

I've not looked into the Moly-coating. Its for swaging?

It's for any kind of lead projectile, cast or swaged, as a post process. In my experience it's a little cleaner (for the shooter) than dealing with straight lead. Some claim a velocity improvement - hard to say among other variables. I do prefer it to bare lead. Poly coating (basically powder coating) is another option that has some fans among powder burners.

If you don't mind sharing your materials, times and temps for hardening and tempering, I'd be happy to know them. If not, I understand, and appreciate what you've contributed here.

GsT

 

[Coxworkshop]

It's for any kind of lead projectile, cast or swaged, as a post process. In my experience it's a little cleaner (for the shooter) than dealing with straight lead. Some claim a velocity improvement - hard to say among other variables. I do prefer it to bare lead. Poly coating (basically powder coating) is another option that has some fans among powder burners.

If you don't mind sharing your materials, times and temps for hardening and tempering, I'd be happy to know them. If not, I understand, and appreciate what you've contributed here.

GsT

Cool I'm going to look into the moly coating

Yes happy to share my heat treat numbers. Like I said I use A2 Steel. Since I have a heat treat oven I have the luxury of fairly precise heat treat temperatures. I let my dies soak at 1750f for at least 15 minutes. I foil wrap (in 309 foil stainless steel) the dies first. Not strictly necessary but it prevents the parts from getting a bunch of decarb. A2 is considered a "still air" quenching metal. Meaning you really don't need to do anything special to quench it. Just let it cool on its own. Because I foil wrap mine I do need to assist a bit with the quench otherwise it cools too slowly. So I clamp between two big pieces of aluminum until I'm sure its under 1300f and then I can remove it from the foil. I then follow a forced air quench, meaning I blow compressed air on it for about 60 seconds. From my testing the die is about 61 hrc at this point.

Once the part is cool enough to handle and the oven has cooled to 1000f I start the temper. I temper at 1000f for 2 hours, twice. This is a pretty significant temper. This brings the dies down to about 50 hrc. For a frame of reference most pocket knives are in the 57-61 hrc range, I do this because I'm still going to machine the dies on the mill and its a bit easier on my carbide tooling.

If you are willing to pay shipping and only have a couple of dies you would like heat treated I'm happy to do it for you. Wouldn't cost me any extra if I do it at the same time I'm heat treating my own stuff.

 

[Coxworkshop]

Excellent work! I don’t think most realize how difficult it can be to make a swage die set that actually works. I have made several and I am still learning.

What do you use to machine yours?

Dave

I have a cnc mill. When you have a hammer everything looks like a nail...same thing applies with a cnc mill. Everything seems like a cnc mill project