So I was rummaging around some old reloading supplies I inherited and came across some oldies. Western Tool Copper Works, 25 caliber, 100gr bullets, along with some old Sisk 224 cals and other neat treasures. Having only read about the old stuff in some of Elmer Keith's writings, it was interesting to see how these bullets were made with copper tubing swaged shut on one end and pointed on the other. Anyone ever use them? If I rember right they were pretty soft and explosive.

Yes I have.
The copper tubing does like to foul the bore more so than today's jacket material but the bullets do obdurate very well in the bore due to the soft copper. Very Accurate.
I still have several loaded round in .25 Newton in my collection.
I only shot targets and not game so I have no info on performance.

The original Barnes bullets were made the same way -- simple copper tubing with a core of lead swaged closed at the bottom and into an ogive with exposed lead at the top. Pure (or near-pure) copper expands easily and broadly when it strikes the target, but it "wipes" off in the barrel's grooves pretty readily, which is why Barnes originals, Swift, and a few other bullets with unalloyed copper jackets perform well on game but tend to foul barrels quickly.