I understand that a certain gunzine has run an article implying that the 145gr .357 Mag Silvertip is new on the market. However, my sources indicate that it was actually introduced in 1982, at the same time as the .38 Super and .45 Colt Silvertips.
To give the writer the benefit of the doubt, despite his notorious history of resubmitting previously published articles, has there been some sort of product-improvement program going on with the Silvertip line?
In addition, the 145gr has been the only weight for .357 Mag Silvertips, correct? I know that there have been three weights in .38 Special (125gr, 110gr, and the discontinued 95gr).
As far as I can recall, the .357 STHP has always been 145 grains. I think I have been buying it since the mid-1980s, and except for the box and tray designs, I have noticed no changes. I am unaware of any product-improvement program.
A quick check of the Winchester ammo website shows me nothing different from what I've seen in the past.
This ammo was what the FBI would authorize for use in .357 revolvers (usually for reloads, with .38 +P ammo loaded in the gun), and that is the context that this load first came to my attention.
The only thing relatively new of which I am aware is that Winchester now sells the STHP bullets as reloading components. As best I can recall this started roughly a couple of years ago.
First of all, the "Silvertip" was originally applied to a Winchester rifle bullet in the late 40s or early 50s.
The Silvertip handgun bullet was designed by one Henry Halverson (I think 70s but I'm not sure about that) and was novel in two important areas:
If you look at the base of one you will see the lead core just as you would with typical fmj bullets. The hollowpoint was created by a punch into the nose (so to speak) which was different from previous types which typically had a solid base.
Silvertip bullets vary in metalic composition by caliber. For example the .32 ACP Silvertip jacket was actually aluminum whereas the heavier calibers had traditional jackets that were plated.
None of the popular handgun hollowpoints arrived in finished form. All have evolved due to a number of factors. Historically the size of hollowpoint cavities varies as does the skiving (cuts) on the nose which help direct the failure lines. The Hydra-shok is a great example because the size and shape of the center post has changed several times. Skiving has changed on Silvertips as has the antimony content of the lead core. I think there was a program to "improve" the bullet that was basically ongoing.
Actually there is a lot of science involved in the design of hollowpoints because different weights and velocities require different sizes and shapes. A good eample of this is seen with the three weights of Gold Dot .45s (185, 200 and 230) for all are considerably different.
One of the things that came about due to the FBI ammo tests was a study of what it took to make bullets expand even when the nose was plugged with cloth or other barrier materials. Actually this is some pretty cool engineering because the hollowpoints were designed to be "self cleaning" as the bullet expanded in the target. One way to do this was to design the cavity so the plug could actually compress and let the fluid get inside the hollowpoint just enough to start expansion (often with the aid of both internal and external skiving). Once expansion began it was relatively easy to make the bullet do what they wanted the hard part was getting it started.
The important thing to understand is that ammo is subject to changes we cannot see as both tooling and materials evolve.
The Silvertip rifle bullets go back to at least 1946, at which time they were being loaded in the Western ammo line featuring the grizzly bear boxes much prized by ammo collectors. I'd have to go back and check some of my earlier Winchester and Western catalogs, but it would not surprise me if the bullet predated WWII.
As for the handgun bullets, I did not mean to imply that they have remained completely unchanged over the years, just that the weight in .357 Magnum has remained constant and the general appearance is similar. It would not suprise me a bit to hear that that bullet has had core and jacket alloy tweaking, as well as tweaking of the size and shape of the hollow-point and the skiving.