You are correct on the TUNGSTEN MATRIX shells they are safe in older steel barrels. I too have used them in the past (they seemed like they were loaded pretty hot though) until I started loading my own bismuth and ITX-10 shells. Most tungsten shell on the market today are harder than steel they have monikers of HW-13, HW-15, HW-18 and TSS.


After the first shot the rest are just noise.