Air Rifle HP slugs

[kimoleto]

After a lot of work I made a swaging press thanks to this forum, I´ve been experimenting with slugs for my .30 and .40 condor airforce rifles. Corbin explains a two staged method for making big cavity hp slugs, so far it has not work for me. http://www.corbins.com/airgun.htm
I´m totally new on swaging, only have an old atlas 618 lathe an a sieg X2D minimill (no previous experience on machining), I ve made my dies from aluminum or soft iron, no way I can work with steel. They work, I´ve made a lot of slugs for my rifles and perform decently. Any one can offer a better explanation on how to make big cavity slugs? I ve even had some luck with fragmenting slugs (used a torx tip as a marker) but so far no luck with the other kind. Normal HP slugs are ok but would like to learn a little more

[kimoleto]

Got some improvements with a different hollowing pin but is not there yet....also found I made an error on my press construction, so i hav more changes ahead

[clodhopper]

I have been working toward the same goal, swaged airgun slugs.

I have to admit it might be easier if I wasn't always standing in the way.

As a new to machining, retired hobbyist, I have some pretty nice tools, Precision Matthews 12X28 lathe,
and Tormach 1100 mill.

Made some dies to make .357 bullets from 9mm brass, and .452 bullets from .45 auto brass.

For the airgun slug I want to make my own 2 flute reamer, Made some 3 flute reamers but they were pretty difficult to measure.

Right now deep in a rabbit hole building a fixture to shape the relief angle on the flutes. But before that, the same fixture has to be square to and ridged enough turn the shaft true on the cheapy grinder.

Bob Strene, an occasional poster on the air gun threads of this forum, has mentioned that best accuracy for air gun slugs often come with slugs sized under bore by .001" to .003".
With this advice it would seem a good plan is to make the die small, shoot a few to see how it goes, and if unsatisfactory, polish out a bit more and shoot again.

Keep working on your lathe, guys have improved thier harbor freight mini lathes enough to cut steel.
Your atlas should be able too.

[kimoleto]

Thanks for answering. I just noticed that AVS uses an insert in the slug to form the big cavity , looks like a plastic bead or something like it. I´ve been playing with different slug weights and discovering how to use the swaging press, I´ve made some advances and discovered some mistakes I made. When I read about your lathes and tooling I can only dream, they are ultra expensive here but anyway its fun to be involved in this crazy hobbie

[clodhopper]

At my stage of learning machining, mistakes are the best learning. Big focus on no blood spillage.

Those insets you mention, I have never seen one, but have read about them on this forum. I think, most any soft plastic thing can be used. They need to be inexpensive, small enough to fit in the cavity, and soft enough to form rather than shatter.

A good machinist can over come the flaws of his machine to produce very good parts.

[kimoleto]

I ve never heard from them before (inserts) can you help me with a link?
So far learning has been great and relaxing, something totally different from my usual work.
I´ve never seen or heard about airgun slugs in Mexico,with our present situation firearms are dangerous even if you register and have a carry permit so all my artillery is stored for the moment. Airguns are an option as they are still considered mostly as toys and we have no legislation for them, so far no restrictions.

[clodhopper]

It's been a few years back. My google-fu is weak.
Already doing manual forum searches for info on cutting a blank barrel for 1885 Winchester, a project on the cusp of start cutting.
Maybe some one here knows where to find it easy can post a link.

[kimoleto]

Wow, cutting a blank barrel...that sounds like a dream job for me, enjoy your project. I´ll look for the post

[clodhopper]

Well it does have a rifled hole, hopefully near the center.

This will be the first barrel install for me. Have to turn it down, thread, chamber it, cut for exractor, Cut three dovetails.

[kimoleto]

Hope it all gets perfect. I have some old Mausers waiting for new barrels, someday I have to learn how its done

[kimoleto]

Just found that my die is slightly tapered , a long slug (80 gr), measures 7.65 mm at the base and tapers to t 7.61 mm just before the ogive starts... the top punch can not enter more than 1.5 mm in the die so I was not being able to get light or really constant weights (thats also the reason of not getting lead bleeding)... the slugs chamber perfectly on my condor and accuracy is good at 25 m, I live in a 6 million people city and Im not being able to shoot outdoors so far. So I have to ream the die, make another one or make a tapered top punch (I modified a reamer to make the cutter so I have to check it carefully)... I´m a self taught lathe/mill apprentice so I made a lot of mistakes and not many sources of knowledge, as you already noticed english is not my mother tongue, swaging language/nomenclature is hard to understand sometimes but the results are enjoyable

[clodhopper]

Alter the cheapest part first. You have less time into the punch.

Maybe you could make a gage pin, turn it to 7.64 mm to see how far it goes in

[kimoleto]

Excuse me base measurement is 7.75 mm A 7.64 goes 3.5 mm into the die, 80 gr bullets are 14.3 mm long. I´ve been trying to make a tapered pin but so far its been a real challenge for me, the taper must be exact otherwise lead flows out from the base. Still in the learning process.

[kimoleto]

Not the best photo but this is what I get:


81.3 gr, no flashing, concentric and shoot OK, problem is there is no repeatability, I get all kind of weights SD is >8 gr . Might seem dumb but its been really difficult to get here, I started from 0, bought a Lee classic cast but did not like the system, the post "making a swaging press" got me into this

[clodhopper]

So a gage pin 7.74mm will show you how much of the punch length should get tapered.
That might be enough to get some lead bleed out.
If not, turn another pin to 7.73mm

[kimoleto]

Yes, I got the idea, dummy me...Thanks

[kimoleto]

You were right clodhopper, I made punches with tapers from 9 to 12 degrees, I got something around 11 degrees plotting the measurements and finally got it.... I made several slugs in different sizes/weights still some minor adjustments required but its getting a lot better, got some flashing, paper thin and easily discarded but now I got the idea

[clodhopper]

Hope they shoot good!

[kimoleto]

Now I´m bending my extraction pins, I´m sure they have no contact with the top punch (Checked without die but with pin and top punch in place), my pins are made out of stainless steel, 2 mm diameter (0.078") with a tip of 1 mm (0.037")... Corbin gives dimension that are to big for a .30 bullet (0.134 to .148" for the metplat extraction pin). I use this tip to form the hollow point, making the smaller diameter and a slight taper helps a lot in the extraction process. I blieve they are still to big as sometimes
get ragged tips (a problem/solution also described in Corbin´s literature). Question is, can I use spring steel? O1 is not available for me in small diameters (1/2" and up only), but close to home there´s a spring factory, they have 1070 and 1080 spring steel in a lot of small diameters, can I use it? Do I have to temper it? Ideas about diameters?

[clodhopper]

I have been buying "music wire" for small punches. I don't know what alloy it is, but it can be bought at the local hardware store in many sizes.

I have also used music wire to make small coil springs, usually wrapping it around a mandrel chucked in the lathe. Then tempering after bending. 400 degrees F. for 1 hour.

Some stainless steel is pretty soft. Store bought music wire is stiff.