204 X 6mm

[Varmint Killer]

Have any of you tried this, necking up the 204 to 6mm? I have a Sako Vixen in 223 that I was considering to re-barrel to a 6X45, but looking at that 204 case and the Vixen, it seems that it would be an ideal light weight dual purpose rifle with little more humph. Any feedback? Thanks!

 

[17 squirrel]

Personally I would go with a faster twist 1-7 or 1-8 barrel and chamber it in 223AI... You can then reliably shoot heavier bullets with alittle more Humph than 223

And if you really want 6mm I would just go to 243. And save yourself the cost of custom dies versus standard dies and off the shelf ammo.

 

[avboiler11]

I haven't done it, but people that have say its performance is almost identical to 6TCU. Are you thinking a slow or fast twist barrel?

I've been thinking of a 6x45 for my kids (assuming in the coming years Indiana sees the light and approves rifle cartridges for deer) and have been told a 20" 1:8 can get a 105 Amax to 2600fps using 8208XBR, which is 308-level external ballistics for a mere fraction of the recoil. 6mm-204 (6x47AI) or 6TCU should be good for another 75-100fps above that.

I do like the 223AI suggestion above - my 22" 1:7 223AI sends the 80 Amax @ 2950fps which also makes for good deer/coyote/chuck medicine with little recoil.

 

[6mm Shoot]

I have a 6mm X 45 and like it very much. I am getting 2600 FPS with 85 gr HPBT using Sierra bullets. I am getting .5" groups at 100 yards out of a 20" barrel. I am very pleased with the out come of this build.

As far as the 243 goes I have two, a Savage and Encore. The Encore will out shoot the Savage. I get 2800 FPS with a 22" barrel and 100 gr bullets. With the load I am using I get 3/4" at 100 yards.

I don't feel that giving up 200 FPS and 15 gr of bullet is giving up much with that kind of accuracy. I mostly punch paper and can't hunt with any of them in Indiana on deer. So the 6X45 will be getting most of the use till I come up with a better load for the 243.

OH, recoil with the 6mm x 45 is very light. I have no proof but I would say it is about half of what the 243 is.

 

[Yote7mmSlayer]

Isn't the .204 a .223 necked down ? So wouldn't this basically be a .223 necked up to 6mm?

 

[avboiler11]

Isn't the .204 a .223 necked down ?

No.

It is a 222 Remington Magnum necked down.

 

[17 squirrel]

Isn't the .204 a .223 necked down ? So wouldn't this basically be a .223 necked up to 6mm?

The 223 necked down to a 20 caliber is the 20 practical..

 

[Onebad06vtx]

Wouldnt that be a 6 x 47?

 

[17 squirrel]

Nope the Twenty Tactical is,

.223 Remington case, necked down to fire a .204" caliber bullet. The .20 Tactical was designed by Todd Kindler and predates the .204 Ruger factory round. The case has approximately 3 grains less powder capacity than the popular .204 Ruger. Handloaders can get velocities with 32 and 40 grain projectiles that almost match the .204 Ruger. Furthermore the .20 Tactical is also able to achieve these velocities with less powder than the .204 Ruger by more efficiently using high energy propellants such as Alliant Reloader 7 and Winchester 748. Based on the .223 Remington, a wide selection of brass is available. Lapua produces high quality cases in .20 Tactical sold under the Dakota Arms brand.

 

[Onebad06vtx]

A 204 necked up is the same thing as a 6 x 47.
Which is a 222 rem mag case necked up to 6mm.
A 222 rem mag case necked down to 20 cal is called a 204 ruger.
The 6 x 47 is a great round.