Can someone tell me the difference in the 6mmx45
and the 6mm TCU. the drawings in my loading
books seem to be identical, but RCBS lists diferent dies for them.
Thanks

Lyle

Different shoulder angle 40 for the TCU and 45 for the 6x45
Slight differance in taper
There is also a differance in where the shoulder starts.

I don't have my book with me to tell you exactly haw big the differances are .

The 6 TCU has slightly less case capasity .
Hope this helps.


Johnch

I don't have the case dimensions, but generally the 6X45 retains the same body taper and shoulder as the original .223 Rem. while the body of the 6mmTCU is "blown out" with much less taper and sharper shoulder.

The 6x45 can be used in semi-autos.... while the 6mm TCU is better in single shot and bolt action guns.

The 6mm TCU has greater usable case capacity.... so don't use 6mm TCU max loads in the 6x45.

YUMAN, if you have access to a the Sierra Rifle and Handgun 4th Edition reloading manuals, you'll find info on the 6x45 in the rifle reloading manual and info on the 6mmTCU in the handgun manual (single shot pistol section).

Note that the 6x45 is loaded to an OAL of 2.26" in order to fit magazine fed (.223 type semi-auto) rifles.

The OAL of the 6mmTCU is listed as "optional" and is usually loaded to a much longer OAL for single shot pistols and rifles.