The 6UM

[Ryan Avery]

How bout this, let's not even associate 6um 30° with 6saum, because they're not the same thing. Headspace for the saum family of cases has been saami spec's since 2001.

After near 25 years UM says that their version of a 6saum isn't the same headspace as 6.5 7 and 300s have been using. Reasoning for this, UM get to set the standard since nobody has ever made brass for a 6mm version of saum(Jake's exact words). Decisions were made at UM to make them not interchangeable, why, well we can all makes guess on that.

The purpose of the brass wasn't to get 6 Saum brass. It was to get 6UM brass. The spec is where the shoulder sits when ADG necks it down.

 

[Tx_300wsm]

I’m wondering if I should change my 6um brass order to 6.5 saum and neck it down the …old fashioned way? I’ve had my prefit 6um barrel for a while now. Will I have issues using the 6 um brass or will I be good to go with fire forming?

 

[The Guide]

I’m wondering if I should change my 6um brass order to 6.5 saum and neck it down the …old fashioned way? I’ve had my prefit 6um barrel for a while now. Will I have issues using the 6 um brass or will I be good to go with fire forming?

I believe the 30⁰ 6UM is the one they are waiting on the reamer for. The 40⁰ that needs to be fire formed is completed and unchanged.

Jay

 

[Ryan Avery]

I’m wondering if I should change my 6um brass order to 6.5 saum and neck it down the …old fashioned way? I’ve had my prefit 6um barrel for a while now. Will I have issues using the 6 um brass or will I be good to go with fire forming?

There is zero issue with FFing the 6UM brass.

 

[Miflatlander91]

So if a guy were to go with the 40 degree shoulder and adg brass when it’s available will it all play together with the whidden dies when they become available again?


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[amassi]

So if a guy were to go with the 40 degree shoulder and adg brass when it’s available will it all play together with the whidden dies when they become available again?


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Yes


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[Lawnboi]

If Winchester can saami the 6.8 western, UM can saami the 6UM!

 

[HighUintas]

Someone would have to give the Hornady folks a handy though in order to get ammo and component support.

 

[GoatPackr]

Someone would have to give the Hornady folks a handy though in order to get ammo and component support.

I'm sure UM would handle the ammo manufacturing part. Maybe start their own bullet manufacturing.

 

[ljones500]

Curious if anyone has found alternative bullets that hold together reliably at these speeds/RPM besides the 115 DTAC in a 7.5tw 5R.

I’m looking to try:

• Berger 105 Hybrid

• Berger 108 Elite Hunter

• Hornady 108 ELD-M

• Match Burners

I’m concerned about potential issues with these bullets holding together at around 330,000 RPM. Does anyone have long-term experience with any of these bullets at 6UM velocities? Would love to hear about both positive and negative experiences with accuracy and terminal performance.

 

[rousseb]

Anybody work a load with the 80gr. Eldvt? Curious for coyotes.

 

[GoatPackr]

Curious if anyone has found alternative bullets that hold together reliably at these speeds/RPM besides the 115 DTAC in a 7.5tw 5R.

I’m looking to try:

• Berger 105 Hybrid

• Berger 108 Elite Hunter

• Hornady 108 ELD-M

• Match Burners

I’m concerned about potential issues with these bullets holding together at around 330,000 RPM. Does anyone have long-term experience with any of these bullets at 6UM velocities? Would love to hear about both positive and negative experiences with accuracy and terminal performance.

I know the 108 eldm doesn't like my 7 twist at 3350 fps.
I used them for fire forming. Somewhere around 100 rnds on the barrel they started not making to a 50 yard target.

 

[ljones500]

I know the 108 eldm doesn't like my 7 twist at 3350 fps.
I used them for fire forming. Somewhere around 100 rnds on the barrel they started not making to a 50 yard target.

Thanks, What barrel and length?

 

[GoatPackr]

Thanks, What barrel and length?

26" Ace
I actually had more room for pressure but was just fire forming.
I'm running 90HHT at 3560 fps.
And it's the 6-7PRC cartridge

 

[Ryan Avery]

Curious if anyone has found alternative bullets that hold together reliably at these speeds/RPM besides the 115 DTAC in a 7.5tw 5R.

I’m looking to try:

• Berger 105 Hybrid

• Berger 108 Elite Hunter

• Hornady 108 ELD-M

• Match Burners

I’m concerned about potential issues with these bullets holding together at around 330,000 RPM. Does anyone have long-term experience with any of these bullets at 6UM velocities? Would love to hear about both positive and negative experiences with accuracy and terminal performance.

I wouldn't trust the 108 ELDs

I have shot the MB and 108 EH out of my 7TW with no issues.

 

[GoatPackr]

I wouldn't trust the 108 ELDs

I have shot the MB and 108 EH out of my 7TW with no issues.

At what speeds?
What barrel length, 20" ?

 

[omicron1792]

Anybody work a load with the 80gr. Eldvt? Curious for coyotes.

Second on this. Do they make it to target. Love my 100gr eldvt load from 6.5prc at 3335.

 

[ljones500]

I wouldn't trust the 108 ELDs

I have shot the MB and 108 EH out of my 7TW with no issues.

Great info, thanks! What speed and approximately how many rounds on the barrel when you shot those?

 

[GoatPackr]

Second on this. Do they make it to target. Love my 100gr eldvt load from 6.5prc at 3335.

If you are shooting that bullet you should be good with a slower twist. No need for faster twist unless running the longer bullets

 

[Tx_300wsm]

I’ve been curious about this too. I originally had an 18” 8tw barrel on order but ended up switching to a 7.5. I’m strongly considering running the eldm’s but don’t think they are going to hold up. I just need to pony up and buy a barrels worth of dtacs.