Swage tooling for diablo pellet

[Eyerelief]

After 15 months work, I finally have been able to build up some swage tooling for pellet making.  I'm slow I know.  This started off as a "I wonder if I could make this with my equipment in my garage?".  First was the 20 caliber then used the same design for .177. 22, and .25.  I patterned off of the Chinese tools as I like their design the best.  Using precision ground A2 tool steel for most of the tooling, not hardened but with the mass of the tool vs the softness of the lead and the size of the pellet, I don't think it needs to be. I am amazed at the improvement in accuracy in my guns. This tool is the .20 cal

[Long_Gun_Dallas]

Very nice 🙂 just out of curiosity, how many hours do you think it would take for you to make one die start to finish?  Or rather how long did it.  A lot of my projects careen wildly out of control in regards to the amount of time they take 😂

[Eyerelief]

I'm right there with you.  Everything I do seems to take 5X longer than I think it should.  My wife now holds a calculator in her hand when she asked me how long it will take for me to do something.

I am sure my efficiency improved as I went along.  The first one took countless hours as I tried different things and made changes like putting two different size pins in so that the guide plates and body halves could not be turned around and I started burnishing the inside of the guide pin holes and the guide pins to really dial in the accuracy of the punches.

To answer your question, I don't exactly know but I'm sure I cant make one in one day, but pretty sure when I did the 22 cal I finished in under two.

[AmBraCol]

Thanks for sharing these with us. Lovely work you did.

[Long_Gun_Dallas]

I'm right there with you.  Everything I do seems to take 5X longer than I think it should.  My wife now holds a calculator in her hand when she asked me how long it will take for me to do something.

I am sure my efficiency improved as I went along.  The first one took countless hours as I tried different things and made changes like putting two different size pins in so that the guide plates and body halves could not be turned around and I started burnishing the inside of the guide pin holes and the guide pins to really dial in the accuracy of the punches.

To answer your question, I don't exactly know but I'm sure I cant make one in one day, but pretty sure when I did the 22 cal I finished in under two.

Haha, that's too funny. 

That's really not too bad, but it was the getting there, haha.  End product looks pretty much perfect.  Well done   I'd like to attempt the same some day.  But it'll be a ways off till I get around to that specifically.

[Insanity]

That is incredible heck I would trade you some of my cast .22 from my 217-20 and 24 molds and heck some .25 cal  wadcutters.

[darkcharisma]

Excellent work, I would like to know what you used to make those cavities? I actually would love to hear or see how you did it all. I would be interested in making a 1 hole die...

IF you have to sale one of those, how much would you charge? I want one, but i want that is hardened from D2 steel.

[Eyerelief]

I appreciate the kind remarks!  The tools are actually fun to make..................now anyway.  I built up a very accurate fixture for my mill.  I used a CAD program to design my pellet then had a tool grinding shop make me the cutters.  I don't know if they did it themselves, (I doubt it) or sent it out to be done.  They were expensive.  I didn't have a great reason to use A2 other than I have experience with it and it mills wonderfully.  D2 would be a good choice as well.  Do to the mass of the A2 I didn't see a need to harden the tool, and I get almost zero flash at the parting lines.  I was more concerned with the metal moving a little after the hardening process and making an inaccurate pellet.  The only downside I see with this set up is that it could rust a little easier if not wiped down after handling.  Not a big deal.  One huge upside is that I can tinker with the punches adjusting weight by changing the contour of the punch until I get exactly what I want per gun.  One tool with 4 different designed punches to get what each rifle likes best.  I have 4 old Sheridan's that shoot these for example.  Each will have its own punch for setting the cavity in the back of the pellet.  Punches are turned ground and polished steel, cheap.  Another big positive is no waste.  I save the extruded flow out the top of the tool and melt it back down into billets and re-extrude into more wire.

I'm trying to wrap my head around cost, the steel set me back about $150-$160 per tool and then the time.  I have given out enough pellets that I have friends now wanting tools.  My boy likes making the pellets, but he built up a stash pretty quick.  Make pellets, shoot pellets, make pellets, shoot pellets........

[AmBraCol]

If you were to make some up as one or two hole dies I'm sure you'd find a market among some of us.   

[CraigH]

That is a great piece of work, Richard!    The amount of effort and skill needed is the furthest distance from trivial possible!

[Eyerelief]

Thanks Craig.  Its been an interesting journey.  I notice you are in Lone Tree.  I just relocated back to my home state Texas after working up there for 25 years.  I commuted from the Rock to the Tech Center everyday since '94 so I know Lone Tree all to well.  I had to move because of Cabela's. I didn't seem to have the ability to drive by it everyday without stopping in.

[darkcharisma]

theres a big  Cabelas around Dallas Texas overhere

[subscriber]

Nice job, Richard!

The beauty of A2 steel is that you don't have to oil quench it to harden it.  This minimizes distortion of a finished or near finished tool.   Just heat to a bright red and then blow cool air on it with a hair dryer, set "cold".

Heating the steel will scale the surface, so you can "paint" the cavities and working faces with anti-scale clay, such as this: https://www.brownells.com/aspx/search/productdetail.aspx?sid=49084&pid=23076

Or, you can leave the cavities undersized by 0.0005" and polish out the rest after heat treatment.  This would require a new "undersized" (expensive) cutter...

You could try it with your existing cutter, and live with the pellets being slightly larger in diameter.

I think you are going to find that the un-hardened mold loosens up and dings easily in annealed condition.  Maybe not if you use it very gently, but it is only slightly harder than mild steel, to facilitate machining.

[Eyerelief]

Awesome info Subscriber.  I am building a bunch of these at the moment and thinking I am going to harden one and see how it does.  I was going to try old school first, wrapping in foil trapped with some paper trapped inside (to ignite and consume the oxygen) to try and limit the scale.  I am also on the hunt for a good 6x12 surface grinder, I think you know where that will lead.  I am detecting wear on my cavity cutters now so I will be buying new ones soon.  As far as needing to buy undersized tools I have mixed thoughts so I will lay this on you and ask for your input:

I am making sets of resizing dies for pellets now in these four calibers.  These dies insure a perfectly round pellet and allow users a chance to try different diameters to find exactly what size works best in their guns, sizing down a half thou at a time (I have some very accurate reamers and some ID burnishing capability).  Making the cavities on size right now.  If I polish and add a half thou, it gives a little more material to work with but my resizing dies will bring it all back in as it reduces diameter on the critical surfaces.

Its lead so I wasn't thinking that adding .0005" to the resizing operation would draw it back to the point of distortion. 

Do you see anything wrong with that thinking? 

[subscriber]

Richard,

Many people on this board size pellets to even them out.  Whatever works should be the motto, but I have some reservations:

A push through sizer reduces the head and skirt to the same diameter.  This may be OK for PCPs, but not for spring air rifles.  The latter need the pellet to resist initial movement, as pressure builds behind them; for full performance, and to reduce piston slamming into the front of the compression chamber. 

Sizing dies with stepped diameters can be made, to size the head and skirt independently.  This may mean a slower process, with a more complicated tooling and mechanism to reverse the pellets back out the die.

Sizing by 0.0005" in diameter is mild and would not displace much metal.  At some larger degree of sizing down, lead will smear backwards against the direction of sizing.   This would tend to create fragile fins, that could become distorted, leading to a loss of accuracy. Now, your pellets could be shaped to have the head and skirt diameters end at a shallower angle.  Thereby reducing the tendency for displaced lead to created thin fragile fins; especially at the back of the skirt  (typical pellet heads already slope at their trailing edges by what would seem a robust degree). 

Sizing down pellets to aggressively lengthens the full diameter "land" at the front and rear of the pellet.  This may raise barrel friction, and reduce velocity a little.  This may not matter for PCPs, but could make loading into a breakbarrel springers more tricky.  Specifically due to the being less forgiving to initial angular misalignment, as the pellet is pressed into the chamber.

Also, aggressive sizing in one step might take enough force that would cause the pellet to be distorted by the punch used to drive it, unless a custom fit, to match your base punch.

[Eyerelief]

Understood. The sizing dies I am making have a separate die for head and skirt. They stack in thick wall tubing for alignment.  This allows a change  in head size without changing the skirt.   The current cutters are producing on caliber cavities so my original idea on the resizer was just to confirm concentricity.  The idea of changing diameter was an afterthought.

[subscriber]

Very clever, Richard

As long as the clearance between the tube and head a skirt dies does not allow the head and skirts to have ambiguous or variable concentricity.  In that case, the concentricity that you engineered into the pellet may be compromised.

Perhaps the head and skirt dies could have a conical nesting feature that ensures alignment between the important bits?  Unless you are achieving sub 0.0005" concentricity as is...

[Eyerelief]

I like the thought of registering one die off the other, hadn't thought of that.  What I do have is very close as I am reaming the die holder just undersized and then burnishing the same ID to open the last couple tenth's.  To hedge my bets I am also making these at sets at the moment ie making the skirt die and multiple head dies in the same fixture at the same time.  I am waiting on some set screws at the moment as well as a die grinder buffing wheel to polish the lead in chamfer of the dies (I chamfer before I ream but I still feel an edge when seating the pellet, but no marks on the pellet). When they come in I will post a pic.

With .010 delta between the head diameter and the skirt diameter, I believe what I have will carry the mail.  I am going to give serious consideration to your suggestion though.  Anything to make a better mouse trap if you will.

[subscriber]

Richard,

You sound like a skilled tool maker.

I think the typical difference in diameter between head a skirt diameters may be less than 0.01".  Oddly, this delta does not fully scale with increasing caliber.  Two reasons for this are that the perimeter of a larger caliber skirt is longer, so already providing more resistance to the pellet "starting".  Then, larger pellets tend to have more weight for their area (higher sectional density); so more inertia compared to the bore area air can push on.

So, what are the typical values for skirt diameter being larger than the head?  I think this question can be broken down into; what is the "perfect" head diameter for my airgun?  What is the "perfect" skirt diameter for my airgun?  I don't claim to have measured a representative sample of pellets, and not in calibers other than .177; .22 & .25.  There, the typical head to skirt diametrical delta seems to be 0.08".  I have seen some at 0.06 and some as low as 0.004".

I seem to be arguing about 0.002".  I think the principle is that skirt diameter needs to be a few thousands of an inch larger than groove diameter for springers.  It can be at groove diameter for PCPs, or just over.  What are these diameters for airguns?  That is where your sizing ability comes in:

Certainly, if you start the delta at 0.01" over head diameter, with the aim of sizing to suit, that would seem like a good plan.  So, I have gone from questioning you, to agreeing with your plan .  Consider the above thinking aloud, or at least, confirmation that someone read your post.

[Eyerelief]

Tool maker... Ive been called a lot of things but none as flattering as tool maker.  I did work for an excellent tool maker at one time but am not worthy of that title.  I take him to lunch occasionally and absorb all he has to offer.  I continue to learn and really enjoy the work.
I must come clean.  I have been extremely prejudice and narrow minded in my thinking.  Shamefully I don't know much about and don't own a single springer.  I am a hunter at heart.  With my PCP's and pumpers, I typically push as heavy a pellet as I can to the edge of the sound barrier.  For example, .25 cal 43 grain pellets at 1100 FPS.  I have fiddled around with the .20 caliber because there isn't much of an offering out there.  By reducing the cavity depth and diameter in the back of the pellet, I have been able to get pellets in the 16 grain weight range.
I am sure you are correct on the skirt diameter.  I took a smattering of measurements from a well respected pellet manufacturer and applied my own dimensions from there.  I made one tool where I shortened up the pellet a couple thou and by default the angle of the skirt eroded the max diameter at the back of the pellet.  Other than being a little lighter and a little shorter the pellet shot fine.  I have not checked it past 50 yards so I don't know if the group will open up or not.  The little light is what bothered me and my narrow minded thinking.
Sub, I appreciate you and enjoy your thinking allowed.  I often zoom in a little too close with my scope when selecting a smaller magnification would allow me to better see what is in front of me, if you know what I mean.