204 ruger to 223AI extra long???

[rockhound78]

Idea just popped into my mind, why not use the 204 Ruger case (or 222 magnum) and open the Ruger case to 22 cal and use it in an extended 223AI chamber? Kind of like the 6mm BRX, but with a longer case. Just run the reamer in about another .090". Shoulder would be about .090" farther forward than a standard 223AI, for a bit more powder room. A 223AIX

Just wondering if its been done, and if so, how did it work out?

 

[17VLD]

Maybe Alf made one at some point,I know he really likes the 22/204 and a lot of the cartridges made from a 204 case.He has posted a lot of neat pictures here of rifles and cartridge comparison pictures.The main difference between your idea and the 22/204 is the shoulder being 40 degrees as opposed to the 22/204s 30 degree shoulder.Not sure how much of an increase you would see in velocity or if it would be worth any added expense for a custom sizing die.Seems like it would be fun if you go that route.If you had the reamer and a blank die,it wouldn’t be that spendy,interesting for sure.Pretty sure varmints wouldn’t like it
Matt

 

[varmintshooter]

I think it would be a 222rem mag AI not a 223AI

 

[rockhound78]

I figure that I can just back off the 223AI size die and get it to work and I already have the 223AI reamer, so I figured why not try it and see what happens.

I have a 223ai Savage and if it doesn't work out, I can just cut off the back of the barrel and turn it back into a regular 223ai like it was.

Would be more along the lines of a 222 mag AI, but since I am using my 223AI reamer, I will just leave the name that way.

 

[acloco]

222 Magnum is the parent case for 204 Ruger. So, run the 223 AI reamer a little deep and you have a 222 Magnum AI. I use 223 AI dies to resize brass.

 

[TAJ45]

Wellll, as long as we're moving in this arena of alteration, a bud is hot on the trail of a 6-204. I'm not quite sure why. However, a "Because it's there" and an "I can do it - why not" is the order of the day.

 

[alf]

Here's a visual of the different 22 caliber cases for comparison:

221 FB - 222 - 223 - 223 AI - 222 RM - 22-204 - 22-204 w/80 VLD - 22 Dasher - 22x47 Lapua

 

[Oso]

Don't forget 22 Grendel and soon to be wildcatted 22GT

 

[lb-ft]

6-204 sounds fantastic. I know I love my 6x45 barrel.

 

[Oso]

6-204 sounds fantastic. I know I love my 6x45 barrel.

I did a custom reamer for 6x45AI, which is essentially a 6TCU. The AI / TCU case design is better than the straight-up 204 / 222 Rem Mag case

 

[TAJ45]

I did a custom reamer for 6x45AI, which is essentially a 6TCU. The AI / TCU case design is better than the straight-up 204 / 222 Rem Mag case

Just curious Oso. How so? Inquiring minds you know.

 

[Oso]

Just curious Oso. How so? Inquiring minds you know.

I had the misfortune of a novice shooter loading a 300BO round (picked up off the ground) into a nice AR15 (5.56). Fortunately, no one was injured but it destroyed the rifle. Lessons learned.

I bought a vintage Sako that needed a new barrel so I thought I would like to do a throwback cartridge and I had been fancying a 6x45. I decided to modify it to a 6x45AI to ensure that the cartridge would/could not be accidentally loaded into any .223/5.56. I was quite proud of myself for this "original idea". This was my first wildcat from scratch because there were no reamers out there for 6x45AI. In finalizing the design for the reamer I did a bunch of testing to determine case dimension changes that occur as a 223 is necked up as well as case dimension change for the AI chamber (reduce body taper and blow shoulder forward). I even re-chambered an existing 223 to 223AI so that I would have donor brass and get more accurate measurements. Also, I tested case forming methods (fire-form vs Cream of Wheat) and even the sequence of steps to determine how I could maximize the overall case length. No matter what room I now stand in, I rest comfortably knowing that no one knows more about 80% Fire Forming (Cream of Wheat or as I like to call it Corn Meal). So... like both feet in the crazy... little sandwich bags everywhere with sticky note for different tests. The answer ... no matter what manufacturer's .223 brass or what process you use to case form you will never get the case length to exceed 1.745"

At the end of the day after all my work there is only marginal difference between my 6x45AI and a 6TCU. I could have saved days of time, expense and time of ordering custom reamer, and finally cost of custom dies to fit my chamber. There are reamers, dies, and even brass right off the shelf for 6TCU.

As to my statement of 6x45AI/6TCU being better than 204/222 Rem Mag case it is more of ancedotal. I have a couple of 222 Rem Mags, which is the parent case that the 204 Ruger is designed from. The case capacity of an AI case is the same as the Rem Mag case. The shoulder angle in the AI is better in that it stops case growth...trim your cases once and then no longer really need to do it again. I do like the graceful neck of the Rem Mag case, but it can be a little more fragile especially with a gas gun. The argument about the reduced body taper of AI making it more difficult to extract is mute if shooting with a bolt gun and there are enough AR15 users that can attest to it running flawless.

 

[AWS]

I've been shooting a 6mm-204 for about 13 years now. It is a nice little round, I have a 22-204 reamer with a removable pilot and bought a 6x47 Rem(6mm-222 Rem Mag) barrel the neck and throat are already in the correct place.. I put a 6mm pilot on the reamer and recut the chamber. The shoulder is moved forward and now at 30 degrees so the new designation is 6mm-204 or 6x47 Rem Improved 30 degree (not AI) It has been a great rig that I used to work with Lead Free bullets for coyote hunting.

I have a 22-204, 25-204, and 6x45mm and in a couple weeks the 6mm-204 barrel is getting pulled and replaced by a 20 Practical.

Alf didn't you run a 223 AI reamer in a little deeper and build a 22-204 AI?

 

[centershot]

OSo, Who makes 6mm TCU brass?

 

[alf]

Alf didn't you run a 223 AI reamer in a little deeper and build a 22-204 AI?

I didn't, no, but have seen a post or two where it's been done.

With the 22-204's necks at 30* and minimal taper in the case body, I don't see any advantage worth chasing.

 

[Oso]

OSo, Who makes 6mm TCU brass?

I may have misspoke. There have been some production runs...maybe not currently.

 

[rockhound78]

Made it to the range today to get some velocity readings on some loads. So nice out there, 34 degrees and only about 3-5mph wind. I was suprised to say the least, so after getting velocities, I went over and decided to try out some loads with the 55 vmax, 60gr Nosler bt and the 62 gr BTHP bulk hornady bullet from midsouth.

Nothing with the 55 or 60gr bullets worked, but the 62gr bullets shot very well, for a plain factory Savage barrel and regular accutrigger. Velocity was 3518fps for the top 62gr load with still room to go. 3 shots top left and 5 in top right. Quick measurement was .275" ctc on the left and the 4 shots on the right was the same with the 5th. pulled out of the group.

 

[acloco]

I didn't, no, but have seen a post or two where it's been done.

With the 22-204's necks at 30* and minimal taper in the case body, I don't see any advantage worth chasing.

Brass does not stretch with the 40 degree shoulder.

 

[doggone6br]

Several years ago I visited with Dave Kiff about this very idea.
Like some of you I already had a 223AI reamer but I always liked the 222Mag case, so I ordered a custom 223 AI go guage .090 longer and ran my reamer in .090 deep. I call mine a 222 RUM.
To clear up some stuff I have read in previous post, this is a true wildcat. The shoulder and the body taper have been changed, when using 222 Mag brass. It's not a 222AI
Also the topic of custom dies, I made a .090 shim and used my 223AI dies, worked fine.