My takeaway from RMR is the company has no problems with the LFC dies being used with their 3GH bullets.

mdi255,
For clarity I am using Lee Part #90817, 223 Lee Factory Crimp Die for my .223/5.56. I also use them with other rifle cartridges.
It does use a collet to apply the crimp, but collet is not part of the die family nomenclature.

Probably trying to avoid confusion with the Lee Collet Neck Sizing Die (e.g Part #90954) which uses a collet to squeeze the neck of a resized piece of brass against a mandrel to improve neck uniformity and improve neck tension consistency. I find the collet neck sizer works best when used in conjunction with a small base body die (e.g. Redding #74111) to bump the shoulder back to SAAMI spec. and not touch the neck.

I do use a collet neck sizer on 300 AAC Blackout brass formed from 5.56 LC brass. The brass is formed by removing the decapping assembly from an RCBS Small Base AR resizer die (die set #11107) and running lubed 5.56 cases through the die. The cases are then delubed and cut using a HF min-chop saw and a jig that\’s no longer available. I then anneal, trim to length, debur and final neck size them using the collet neck sizer (no lube necessary). The TTL and deburring can be done after the neck tensioning. I haven\’ noticed any difference.

I also use Lee Carbide Factory Crimp Dies (available for handguns cartridges only), which apply a taper crimp or roll crimp depending on the cartridge (e.g. 9mm is taper, .357/.38 is roll) and final resizes the cartridge with a carbide ring at the opening (it resizes as you raise the ram). It replaces the Lee Bulge Buster that you\’d buy separately and insert into a Lee Carbide Seating Die.

I use both kinds of LFC dies because they are not dependent on cartridge trim length like the Redding taper/roll crimp dies I used for years.

Although I may split a lot of brass and use the LFC on half and the taper crimp die on the other (all other components being the same) and see if there is any apparent advantage of one over the other.