Swaging lead 9mm hollow base

[Traffer]

I just tried my first foray away from 22lr reloading. Made up dies for swaging (lead not jacketed) 9mm hollow based bullets. I am happy with how it turned out so far. Here is a video:

[clodhopper]

Nice view of your press with a lathe in the background.

What tool did you use to cut the nose of your 9mm swage die?

[Sgt Petro]

Thanks for the video! Very nice looking bullets!
I'm intrigued, why a 9mm hollow base? I understand the principle, but what is this particular application?

[Traffer]

Thanks for the video! Very nice looking bullets!
I'm intrigued, why a 9mm hollow base? I understand the principle, but what is this particular application?

The applications COULD be for 9mm Luger. There was a discussion about a year ago about hollow bases sized to have no lube grooves being of superior performance. I also like that they have longer bearing surface and will seat down in the case farther (without sacrificing case capacity)
The other possible application would be in a 38 S&W. Some say that a hollow base in soft lead will allow the bullets to expand and seal to the slightly larger bore of the 38 S&W. But I may make a larger die for those...about .360"-.361" depending what my 38 barrel slugs at. One of the great things about swaging these boolits is that a good mold is not needed. Just need to mold cores. Core molds are very easy to make because they only have one diameter to the ogive. That means that a mold can be made by simply holding two pieces of stock together and drilling holes where they meet. Just drill to the desired depth and attach a sprue plate and pestro! got a mold.

[Traffer]

Nice view of your press with a lathe in the background.

What tool did you use to cut the nose of your 9mm swage die?

I ground a size "T" drill bit into a bullet point and just drilled it with the lathe. Polished it a bit, added the extraction pin hole and bob's my uncle.

[n.h.schmidt]

Hi Traffer Seating the HB bullets deeper into a 9mm case will cause you problems. The I.D of the case gets smaller in most cases. This will cause a spare tire case bulge where the base of the bullet seats. It looks bad and it might not chamber. Or the inside taper of the case will size down the skirt probably reducing any accuracy you could have from the HB. What you have would work nicely in a 38 special as is.
n.h.schmidt

[Traffer]

Hi Traffer Seating the HB bullets deeper into a 9mm case will cause you problems. The I.D of the case gets smaller in most cases. This will cause a spare tire case bulge where the base of the bullet seats. It looks bad and it might not chamber. Or the inside taper of the case will size down the skirt probably reducing any accuracy you could have from the HB. What you have would work nicely in a 38 special as is.
n.h.schmidt

Thanks for that info. I wonder what the specs are for the seating of these bullets. The hollow based ones are longer than the dropped ones from this die but these are pretty short bullets. They are from an old obsolete Lee die which is 358 117 rn. They drop with soft lead (9bhn) at 112 to 114 grains. from the mold dropped at .518". After swaging hollow base they are .3575" and .565" long. I think that is still relatively short but would like to find the parameters for this. Thanks again

[Traffer]

Here are some pictures of the boolits that were swaged properly... powder coated before being swaged. (Smoke's Translucent Copper)

[skeettx]

So, let me understand, you cast 9mm bullets, then you powder coat these bullets, then you swage these bullets, then you load these bullets in a 9mm?
Why would the cast/lubed 9mm bullets not do what is needed?
Has a head to head comparison been accomplished?

Happy New Year

Mike

[Traffer]

So, let me understand, you cast 9mm bullets, then you powder coat these bullets, then you swage these bullets, then you load these bullets in a 9mm?
Why would the cast/lubed 9mm bullets not do what is needed?
Has a head to head comparison been accomplished?

Happy New Year

Mike

It is a bit surprising that so many people are perplexed about this. It wasn't long ago at all that many were talking about the need to resize after powder coating to get consistent diameters. There were also some very interesting threads about the benefit of hollow bases in pistol bullets. But now people are looking at this like it is just stupid folly.

[Bruce A. Frank]

Hi Traffer Seating the HB bullets deeper into a 9mm case will cause you problems. The I.D of the case gets smaller in most cases. This will cause a spare tire case bulge where the base of the bullet seats. It looks bad and it might not chamber. Or the inside taper of the case will size down the skirt probably reducing any accuracy you could have from the HB. What you have would work nicely in a 38 special as is.
n.h.schmidt

With a hollow base, rather than creating a bulge in the case, the skirt of the hollow base could be forced inward sized down to fit the interior dimension of the case. I wouldn't expect that to be detrimental to accuracy. I would expect, upon ignition, the pressure of the powder gasses to actually expand the skirt outward and uniformly conforming to the barrel once clear of the case. Therefore no lopsided base and a good seal preventing any jets of gas blowing the bullet one way or another as the skirt clears the muzzle. Maybe providing the best of all worlds to guarantee best accuracy.

[Goofy]

It is a bit surprising that so many people are perplexed about this. It wasn't long ago at all that many were talking about the need to resize after powder coating to get consistent diameters. There were also some very interesting threads about the benefit of hollow bases in pistol bullets. But now people are looking at this like it is just stupid folly.

I get it, some fellas won’t. Sort of like my CF substitute for RF ammo. It’s been a long time since I loaded any auto pistol ammo, but hollow base bullets for revolvers always make me smile. Put simply, they work well. Don’t see any reason they wouldn’t work for 9mm guns.

[Traffer]

As I am new to the reloading game, I am on a learning curve. One of the things I have learned since posting this thread is the very fine tolerances that loading 9mm requires. One) having a pronounced hollow base throws a variable into the case volume calculations. And two) because of this it also creates a new challenge for the Overall length of the cartridge. It would almost certainly require working up new load data for every gun.
That being said, It COULD reap the same benefits as the hollow base in any soft-ish bullet.
For example as Bruce A. Frank points out, the hollow base could have the benefit of sealing to the rifling.
Another possible benefit is from the greater bearing surface (and with the powder coat, more bearing surface is potentially much better for consistency on target.
Here is a picture of 22lr showing how the hollow base uses the pressure to form fit the rifling. (note the 22lr also has to overcome the rebated heel)

[Goofy]

File this in the FWIW folder: SAAMI spec for 9mm Luger brass has the difference between major and minor case diameter of .011". Yes, it is tapered, but only to a very small degree.



Bullet diameter spec is .3555". Were one loaded with one of Traffer's bullets the base would not bulge the case any more than a jacketed bullet, which is zero.

https://saami.wpengine.com/wp-conten...sting-Copy.pdf