6mm x 204?? anyone try this

[bheadboy]

I have a lot of experience with the 6x47 (222m) and love the cartridge, just thinking, the 204 has a higher water capacity than the 222m, so it should give higher preformance than the early 6x47,

Has anyone tried to get 6mm out of 204 brass, is there enough brass thickness to still have bullet tension?

just thinking of possible build for pd and fun. no competition.

Bob

 

[cb1229]

:-\Isnt the parent case for the 204 a 222magnum any way? do a little home work. check out the hornady site I think you will see that it is

 

[moorepower]

It is the parent, but comparing the two would be kind of like saying since the .222 is the parent case for the .223, just use the .222. The .204 is closer to the .222m ai. One of the main advantages is the use of Norma brass for the .204 and only Rem for the .222 mag.

 

[JohnHenry]

http://benchrest.com/archive/index.php/t-65397.html

 

[bheadboy]

having done some checkin befor posting, the 204 has 3%mor water capacity than the 222m and when opened up to 6mm will have more. this is because the shoulder is moved forward and the angle changed.

my question was in referance to the neck wall thickness, is there enough metal there to go from 204 to 244 and still have bullet tension.

also was interested in any velocities and accury achieved.

Bob

 

[JohnHenry]

Plenty of metal. Some 6 PPC chambers use a case with approx. .008" neck wall. A Nosler 204 case expanded to 22 cal. has a neck wall of approx .0112". Further expansion to 6mm reduces the neck wall thickness to approx .0109". Stevec's post indicated he was getting 3400 fps with 68 gr. Bergers and groups in the low 0.2's

 

[bheadboy]

Thanks JOhn, did you know Al Angerman in Wilmington,
Your data indicates a need for tight neck chamber and dies
Bob

 

[JohnHenry]

No, I do not know Mr. Angerman. Stevec's chamber I believe had a .273 neck. He indicated that should probably be reduced somewhat. I believe I have his chamber print if I can find it. Winchester and Remington 204 brass will have a little thicker necks than Nosler or Norma. I think I would use a no-turn .268 neck designed for the Nosler/Norma brass. Wilson can modify a 204 seater die at a nominal cost and one could open the hole in the shelf where the bushing sits in a Redding fl 204 "S" type die to accommodate the .268 neck.

 

[Chuckw]

i have built a number of 6tcu rifles. not much difference. performance is far above capacity in this case.

chuck

 

[Dogdstr]

Check out the new hogden reloading mag,there is an article on the 6mm-204 in it.Bobby

 

[AWS]

New Member here, saw this post and had to join.

I've been shooting a 6mm-204 for a few years now. It is my goto rifle for called coyotes. I built it for shooting 62gr VGs but they turned out to be too destructive on pelts. 55gr NBT Lead Frees work great as do 58gr V-max and 55gr BK's.

55gr lead bullets are right at 3700 fps and the lead frees are 100-150fps slower due to the space they take up in the case, 24" barrel.

I have built a 22-204, 6mm-204 and a 25-205. The 22-204 pushes 40gr NBT's at 3900 fps (22" barrel). The 25-204 is getting 2800fps with 100gr Partitions and is my favorite deer rifle.