6mm-06 Cartridge Variants

Joined
Aug 17, 2024
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In the hills
Hi y’all! I am creating this thread to learn more about and share information about the 6mm-06 or any of the variants that are .243”/6mm descendants to the old tried and true ‘06 or 270 Win.


If you have any experience with any of these cartridges, please chime in and share your experiences! In today’s day and age, it’s platforms like this that keep these “old dinosaurs” alive!

Thank you in advance from any information!
 
OP
UngulateGuardian797
Joined
Aug 17, 2024
Messages
70
Location
In the hills
After my deep dive into P.O. Ackley’s writings on wildcat cartridges, I have found an inkling to build a 6mm-06 AI (40 degree shoulder). After I fire form my initial 3 pieces of brass to form in my chamber, I plan to send to Hornady to get a custom set of dies made.

So here is my plan:
.25-06 Norma brass necked down to .243.
20” #3 Contour 1-8” twist barrel to shoot 90+ gr. pills
Tikka T3 action (270 Win.)
Stocky’s NextGen Carbon Fiber Hunter Stock
SWFA SS 10x42 MOA
UM Premium Rings
SRS Tikka 20 MOA Rail
Wyoming Arms 4-Squared Silencer
 

Big_wals

WKR
Joined
Mar 14, 2020
Messages
405
Location
W Texas
After my deep dive into P.O. Ackley’s writings on wildcat cartridges, I have found an inkling to build a 6mm-06 AI (40 degree shoulder). After I fire form my initial 3 pieces of brass to form in my chamber, I plan to send to Hornady to get a custom set of dies made.

So here is my plan:
.25-06 Norma brass necked down to .243.
20” #3 Contour 1-8” twist barrel to shoot 90+ gr. pills
Tikka T3 action (270 Win.)
Stocky’s NextGen Carbon Fiber Hunter Stock
SWFA SS 10x42 MOA
UM Premium Rings
SRS Tikka 20 MOA Rail
Wyoming Arms 4-Squared Silencer
No experience with a 6-06, always thought it sounded like a cool cartridge though. Keep us updated on how it shoots!
 
Joined
Mar 28, 2020
Messages
929
I had a 240 Weatherby that was incredible
Today I would create my own version of the 6 mm Gibbs
I would run a 6 mm Creedmoor reamer deep enough to accommodate the full length of 25/06 brass to the front of the neck then neck down to 6 mm and blow the shoulder forward
Tikka action and Waters magazines
 

rayporter

WKR
Joined
Jul 3, 2014
Messages
4,403
Location
arkansas or ohio
used to shoot dogs with one fella that had a 6-06. another had a 240wby. while both were ok, neither ran circles around my 243Ack.

the guy with the 240 also had a 25-06 and it ran circles around the 243A.

i kept the 243A and added a couple 6mm Remingtons to the stable for less hassle.
the guy with the 6-06 rebarreled it to a 6BR and the 240w was turned into a 6mm rem.

the 8 tw barrels all shoot 6mm 55gr bal tips fast and accurate with none blowing up.

make sure to get a couple shots on the brass before you send it in for the die.
 
OP
UngulateGuardian797
Joined
Aug 17, 2024
Messages
70
Location
In the hills
used to shoot dogs with one fella that had a 6-06. another had a 240wby. while both were ok, neither ran circles around my 243Ack.

the guy with the 240 also had a 25-06 and it ran circles around the 243A.

i kept the 243A and added a couple 6mm Remingtons to the stable for less hassle.
the guy with the 6-06 rebarreled it to a 6BR and the 240w was turned into a 6mm rem.

the 8 tw barrels all shoot 6mm 55gr bal tips fast and accurate with none blowing up.

make sure to get a couple shots on the brass before you send it in for the die.
I totally get that.

I plan to run 3-4 shots on the brass before sending it in.
 
OP
UngulateGuardian797
Joined
Aug 17, 2024
Messages
70
Location
In the hills
I had a 240 Weatherby that was incredible
Today I would create my own version of the 6 mm Gibbs
I would run a 6 mm Creedmoor reamer deep enough to accommodate the full length of 25/06 brass to the front of the neck then neck down to 6 mm and blow the shoulder forward
Tikka action and Waters magazines
The 240 Wby. sounds awesome, but the limited availability of brass is the biggest short coming in my honest opinion.

That cartridge sounds pretty cool!
 

jfk69

Lil-Rokslider
Joined
Feb 27, 2023
Messages
190
Seems like that tall powder column in a 20” barrel would be helliously inefficient.
 
Joined
Mar 16, 2021
Messages
3,570
Location
Western Iowa
After my deep dive into P.O. Ackley’s writings on wildcat cartridges, I have found an inkling to build a 6mm-06 AI (40 degree shoulder). After I fire form my initial 3 pieces of brass to form in my chamber, I plan to send to Hornady to get a custom set of dies made.

So here is my plan:
.25-06 Norma brass necked down to .243.
20” #3 Contour 1-8” twist barrel to shoot 90+ gr. pills
Tikka T3 action (270 Win.)
Stocky’s NextGen Carbon Fiber Hunter Stock
SWFA SS 10x42 MOA
UM Premium Rings
SRS Tikka 20 MOA Rail
Wyoming Arms 4-Squared Silencer
This is a great build out and should cover all your bases. I believe @Ross has experience shooting either a 6-06 or 6.5-06 and my be able to provide impressions.
 
Joined
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Messages
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Western Iowa
Seems like that tall powder column in a 20” barrel would be helliously inefficient.
The 6UM solves the efficiency problem for sure, but if OP likes the old school case and isn't concerned about losing some efficiency, it's still a very useful and potent cartridge.
 
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Last edited:

jfk69

Lil-Rokslider
Joined
Feb 27, 2023
Messages
190
The 6UM solves the efficiency problem for sure, but if OP likes the old school case and isn't concerned about losing some efficiency, it's still a very useful and potent cartridge.
Absolutely. My comment was an observation, not a condemnation. Lord knows I’ve done a million things that were anything but efficient lol.
 
OP
UngulateGuardian797
Joined
Aug 17, 2024
Messages
70
Location
In the hills
Seems like that tall powder column in a 20” barrel would be helliously inefficient
I know it’s going to be inefficient. If I was worried about efficiency, I would just run a 6BR.

The 6UM solves the efficiency problem for sure, but if OP likes the old school case and isn't concerned about losing some efficiency, it's still a very useful and potent cartridge.
We will have to see what the old ‘06 case does. The way I look at it is look at the efficiency of the 280 AI in comparison to the SAUM. It intrigues me so I’m going to test one out!

You can get a 6-06 Improved (40 degree shoulder) prefit from Preferred Barrels that meets your specs. for $550. This is in their lite hybrid contour that intentionally supports 5/8-24 threads.

https://preferredbarrelblanks.com/p...el/?gf_token=ce81a78079e244e59f6fc8ddeb55350b

Here is a decent article and some load data FWIW.

https://www.rifleshootermag.com/editorial/ammunition_rs_6mm06wildcat_200808/84344#replay
PBB is who I plan to order from when I order my barrel!

Also, I have read through that article a few times. Thank you though!
 
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