WHADIFIND asked:
> What was the purpose of "swaging" a bullet?
Here's a cut-&-paste of my What-Is-It forum reply to an ID-request about that type of bullet:
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That specific version of bullet is called a "Machine-Pressed-&-Turned" (MP&T) bullet. It was not made by pouring molten lead into a bulletmold. Instead, a lead slug was placed into a machine which compressed the lead slug into the desired shape of bullet. Then, body-grooves were cut into the bullet's sides by a lathe. That is why it is called a "machine-pressed" and "turned" bullet. Due to a naming error in an old book on civil war bullets, we civil war relic diggers call that type a "swaged" bullet, but in actuality it was not made by swaging the lead.
The indented lines in your MP&T bullet's base cavity were made by the part of the lathe machine which held the bullet firmly in position while the grooves were being cut into it. On rare occasions, the bullet "slipped" a little bit when the lathe's cutting-tool first dug into it, causing small ridges to form alongside the indented lines in the base. See the photo below.
The 3-groove .58-caliber "Machine-Pressed-&-Turned" minies with 5 or 6 "spokes" in their conical base-cavity do not show up on battlefields until 1863. (For example, they did not yet exist at the time of the 1862 Antietam battle in Maryland.) Therefore, they are somewhat rarer than the common moldcast-lead versions of 3-groove minies, which were used throughout 1861-65. However, by early-1864 the yankees were using their bullet-making machines to produce multi-millions of the incorrectly-named "swaged" bullets. They have been dug in significant quantities at 1864-65 battlesites in nearly all of the Southern states. So, they are not greatly rarer than their cast-lead cousins.
Rarity-rating info, for Tnmountains:
Rarity-rating on a 1-to-10 scale (with a 10 rating being the rarest). I would rate the unfired 5-spokes MP&T minie at 2.5, and the unfired 6-spokes version at 3. I think their price at civil war relic-shows is a more "tangible" indicator. Typical unfired yankee .58-caliber 3-groove CAST-LEAD minies sell for about $2. At civil war relic shows here in Virginia, nice-condition unfired 5-spokes MP&T ones "retail" for about $5, and 6-spokes MP&T minies "retail" for about $6.
