I bought a bunch of the dillon 1" lock rings last summer. This weekend I finally had a chance to use/test them. In other words, I was running low on several calibers and did a reloading weekend to rebuild the plinking ammo reserves (3K+ rounds). I put together toolheads of several calibers that hadn't been loaded in awhile (and didn't have enough toolheads at the time to leave them setup). I stocked up on toolheads to prevent that issue again.
The purpose of these lockrings is they are small enough to get a wrench on to tighten them while in a toolhead. They are 1" across the flats and normal dies are 7/8"-14 threaded so they aren't much bigger than the die bodies. Normal lock rings are larger and hard to tighten; it's not impossible, just inconvenient. Dillon sells a wrench that fits and also has a 7/16 box end for adjusting dillon powder bars. It's a nice combo and $15 well spent.
The purpose of these lockrings is they are small enough to get a wrench on to tighten them while in a toolhead. They are 1" across the flats and normal dies are 7/8"-14 threaded so they aren't much bigger than the die bodies. Normal lock rings are larger and hard to tighten; it's not impossible, just inconvenient. Dillon sells a wrench that fits and also has a 7/16 box end for adjusting dillon powder bars. It's a nice combo and $15 well spent.