Thread: 6x45 Rem barrel

Originally Posted by Micky Duck

so if Im reading this right .....cartridge is a .223 necked UP to 6mm?????

Yes correct.. nothing fancy.. just a .223rem cartridge necked up to 6mm to allow the use of heavier hunting bullets.
Many of the 6mm weights cross over with the .223 weights but where this 6x45 benefits is with the heavier jacketed bullets more suitable for deer sized game and the 6mm bullets actually take up less case room than many of their longer .223 counterparts of similar weights. This meant the little cartridge can really get respectable velocities from 70 to 95gr bullets.

For those not following here is a quick explanation of the more popular related 6mm wildcat cartridges:

6mm/.222 = necked up .222 Rem std .23deg sholder

6x45 AKA 6mm/.223 = necked up .223 Rem std 23deg shoulder

6mm TCU = necked up .223 Rem fire formed straight wall body and 40 deg improved shoulder

6x47 Rem AKA 6x47 Federal = necked up .222 magnum or some now use .204 Rug brass.

There ate variations on all of these with 30deg and 40deg shoulders etc but those are the more common variants.

I had intended on building the 6mm TCU as that what I was told the barrel was pre chambered in. This was not the case.
I dont have the 6mmTCU reamer so I have continued with 6x45Rem.

However I could cut a 6mm TCU (of sorts) with reamers I do have, start with the 6x45 reamer then follow it with a .223 Ackley improved reamer with a 6mm pilot but the body length and body to shoulder junction diameter on the .223 AI chamber will be slightly larger than the 6mm TCU meaning Id also have to make some custom from some .223 Ackley improved dies. While all doable this was just going to be a quick fun project on a cheap and cheerful project .223 rifle I picked up with a rooted barrel.
I intended to move the rifle on once I was done playing but the one off custom chamber would have a limited market.