6mm on the 222 magnum case

[simo hayha]

Anybody know the difference between 6tcu and 6/223ai ?

 

[Oso]

Not a rumor

Opportunity for OP to do some research and discovery

 

[Oso]

Anybody know the difference between 6tcu and 6/223ai ?

Yes…. If you didn’ t know about the 6TCU and decided to custom design a 6x45AI, order a custom reamer, use 223AI dies until you have custom dies made. Unknowingly you have recreated the wheel and you can be as cool and foolish as me

Or … you can spend 50% of amount to build/buy off the shelf reamer and dies for 6TCU.

There is no meaningful differences so go 6TCU and never look back. If I had a Delorean…

 

[reed1911]

I shoot the 6x47. Great little cartridge. We have tons of .222 mag brass in stock if you need any. Nosler premium, Nosler seconds, and Remington.

Personally the seconds are the best for this. premium brass low price. I'm at between 8-10 and pockets are still tight. I do anneal every 3rd round or so. I do not run them hot.

 

[wildcatter]

I bought a Remington 600 Tomahawk that came with a a 6x45 (6x223), with a vintage McMillan sporter stock. It also had a .223 barrel that was new and unfired for the same action. I had a 6mTCU decades ago when it first came out in a TC Contender. I never thought much of it 40 or more years ago. But a 14" barrel did it no favors!

When I first got this I had no dies or anything just a 223 S sizing die, so I ordered dies from redding, and put a .250 bushing the S die, and used the original owners seater till mine came. Using new LC brass, and a 65 grain bib bullet, I loaded some Benchmark loads. I never had Steller results with and put together 5 loads starting @ 27.0 grains to 29.0 in .5 grain increments.

Benchmark had given good results in my 222 and ppc, just not as good as other powders. So I wanted what the OP is looking for, a 300 yard walk around light gun varmint rig. I got it!! I think every one of those 5 shot groups I initially loaded would work. Everyone 1/2moa or smaller.
3200 fps to 3300 fps was all plenty good, the 28.5 and 29.0 loads I only loaded 3 each because I wasn't sure about pressure, just to see. I settled on the 28.5 after reshooting it and staying in the .326 moa at 3290 fps 5 shot average, and said good enough! I'm sure it can do better, but this is a lightweight walk around varmint gun.

The 222 mag is in my opinion a better cartridge to work with, and with the longer neck, primarily the same powder capacity, I'm sure you will be happy with it. I even loaded 2 85 grain Sierra hpbt's and as you see on the top right target, same results as the 65 grain bullet! But this barrel is a 1-8 twist.

Had I built this to what I wanted for the cartridge, I think a 1-12 twist would be perfect for the 65 grain bullet. I think you could go as heavy as 65 grain but 70 or more with a 1-14 barrel would be less than optimum. But easily 3300 fps, and yes, 300 yards on ground hogs is easy with .3ish moa.

Better cartridge, better action, and 1-8 to 1-14 twist barrel, your going to have what you want!!

 

[DaveTooley]

SELLING Thread '6T (6X47imp) reamer and gage'

Jun 12, 2025

For sale
new Henriksen 6T(42 degree shoulder) .263 nk finish reamer and go gage
$150 shipped

• DaveTooley
• Replies: 0
• Forum: Tools, Dies, Rests, Reloading Components & Misc

• 

 

[reed1911]

I bought a Remington 600 Tomahawk that came with a a 6x45 (6x223), with a vintage McMillan sporter stock. It also had a .223 barrel that was new and unfired for the same action. I had a 6mTCU decades ago when it first came out in a TC Contender. I never thought much of it 40 or more years ago. But a 14" barrel did it no favors!
View attachment 1668910
When I first got this I had no dies or anything just a 223 S sizing die, so I ordered dies from redding, and put a .250 bushing the S die, and used the original owners seater till mine came. Using new LC brass, and a 65 grain bib bullet, I loaded some Benchmark loads. I never had Steller results with and put together 5 loads starting @ 27.0 grains to 29.0 in .5 grain increments.

Benchmark had given good results in my 222 and ppc, just not as good as other powders. So I wanted what the OP is looking for, a 300 yard walk around light gun varmint rig. I got it!! I think every one of those 5 shot groups I initially loaded would work. Everyone 1/2moa or smaller.
View attachment 1668881 3200 fps to 3300 fps was all plenty good, the 28.5 and 29.0 loads I only loaded 3 each because I wasn't sure about pressure, just to see. I settled on the 28.5 after reshooting it and staying in the .326 moa at 3290 fps 5 shot average, and said good enough! I'm sure it can do better, but this is a lightweight walk around varmint gun.

The 222 mag is in my opinion a better cartridge to work with, and with the longer neck, primarily the same powder capacity, I'm sure you will be happy with it. I even loaded 2 85 grain Sierra hpbt's and as you see on the top right target, same results as the 65 grain bullet! But this barrel is a 1-8 twist.

Had I built this to what I wanted for the cartridge, I think a 1-12 twist would be perfect for the 65 grain bullet. I think you could go as heavy as 65 grain but 70 or more with a 1-14 barrel would be less than optimum. But easily 3300 fps, and yes, 300 yards on ground hogs is easy with .3ish moa.

Better cartridge, better action, and 1-8 to 1-14 twist barrel, your going to have what you want!!

Now that is how you do it!