The 6UM

[Elkster23]

I only ask cause I'm doing an 18" 25-7prc. Here is thunderbeasts limits on the ultra 7 ill be using. I think i should be good.
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I run an ultra 7 on my 18in barreled 6um. Around 3250. No issues yet.

 

[Ryan Avery]

I only ask cause I'm doing an 18" 25-7prc. Here is thunderbeasts limits on the ultra 7 ill be using. I think i should be good.
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You will be in the mid-60s on powder. It should be fine.

 

[Brandon.miller.4]

You will be in the mid-60s on powder. It should be fine.

Not to repeat myself, but if there's no issues on 18" barrels why do most seem to be running 20" or more with the 6um? Curious more than anything.

 

[Formidilosus]

Not to repeat myself, but if there's no issues on 18" barrels why do most seem to be running 20" or more with the 6um? Curious more than anything.

Because most people are ignorant on short barrels and already believe a 20” is wildly short; and/or the want more MV hence the 6UM to begin with.

 

[HighUintas]

One reason a person may want a longer barrel is reduced noise/blast. Even if you're using a suppressor on a 16" 5.56, the shooter's ear dB is close to or above 140 for most suppressors tested in TBACs 2024 suppressor summit. A longer barrel will reduce that further, but is one of those personal preference tradeoffs

 

[NSI]

One reason a person may want a longer barrel is reduced noise/blast. Even if you're using a suppressor on a 16" 5.56, the shooter's ear dB is close to or above 140 for most suppressors tested in TBACs 2024 suppressor summit. A longer barrel will reduce that further, but is one of those personal preference tradeoffs

Not comparable to an extra equivalent length of suppressor attached.

-J

 

[rbutcher1234]

One reason a person may want a longer barrel is reduced noise/blast. Even if you're using a suppressor on a 16" 5.56, the shooter's ear dB is close to or above 140 for most suppressors tested in TBACs 2024 suppressor summit. A longer barrel will reduce that further, but is one of those personal preference tradeoffs

These two scenarios aren’t even remotely comparable. ANY suppressed 16” will be massively superior to a barrel length of equivalent caliber, any length. Even with the worst suppressor.

 

[HighUintas]

Not comparable to an extra equivalent length of suppressor attached.

-J

These two scenarios aren’t even remotely comparable. ANY suppressed 16” will be massively superior to a barrel length of equivalent caliber, any length. Even with the worst suppressor.

I'm talking about a 16" suppressed gun vs a 20" suppressed gun.

Not a suppressed vs not suppressed/long barrel scenario

 

[NSI]

I'm talking about a 16" suppressed gun vs a 20" suppressed gun.

Not a suppressed vs not suppressed/long barrel scenario

Yes. And I’m talking about the outsized decibel reduction value that comes from spending additional length on a higher volume suppressor rather than carrying around an equivalent total length made up by a lower volume suppressor and additional barrel. Barrel is for velocity. Suppressor is for …. Suppressing.

-J

 

[HighUintas]

Yes. And I’m talking about the outsized decibel reduction value that comes from spending additional length on a higher volume suppressor rather than carrying around an equivalent total length made up by a lower volume suppressor and additional barrel. Barrel is for velocity. Suppressor is for …. Suppressing.

-J

Yes I agree, but I have 1 suppressor only. So if I'm concerned about shooting it while hunting without hearing protection, I might choose a 20" over 16" for a 6um. This is part of the reason I'm waffling on having my 243 cut back or not. So for someone in the 1 suppressor boat, that may be a consideration for them.

 

[rbutcher1234]

Sounds like you need a second can

 

[Brandon.miller.4]

Good info, had the dominus or magnus cans been available at the time, I definitely would have gone that route for the added volume. For now, I'll use what I have and be happy with my 18" barrel.

 

[Wendlingd15]

So 18 is the sweet spot?

 

[Ryan Avery]

So 18 is the sweet spot?

20" for me. If the barrel is slow, it will still be in the 3200s

 

[Wendlingd15]

If a guy does a tikka action, ace barrel “that light weight profile you had them do” and carbon rock stock what kind of weight are we looking at?

 

[HighUintas]

If a guy does a tikka action, ace barrel “that light weight profile you had them do” and carbon rock stock what kind of weight are we looking at?

Roughly 5.8lbs depending on your specific rokstok

 

[JBahr]

My UM lightened Tikka with, UM bottom metal and detachable mag, 24" Ace wrought iron fluting, and scalloped RokStok weighs 7lbs

 

[djfergus]

Is there a drawing floating around anywhere for the 6 UM 30?

 

[jmw]

What length barrel and twist?

Not to hijack the 6 UM thread, but I just killed this buck with a 108 ELDM out of a 6PRC at 3260 FPS. So more fast 6mm data for others.

He was bedded quartering to me at 180 yards. I put the bullet just inside the shoulder (near the neck). Initial impact “stoned” him. He laid there for about 10 seconds, then worked his way to his feet, stumbled down the mountain about 5 yards and died. Split one lung in half and seemed to kill just fine.

View attachment 627553
Entrance is at the point of the shoulder and you can still see the trauma it was causing back well behind the shoulder.
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What load did you come up with for your 9 twist. Travis is making me a 18” 9 twist 6-saum right now for 90s and Ime curious about your powder selection and speeds
Thanks

 

[jmw]

I ran them up to about 3750 in my 20” 6 saum. Not near as fast as I thought I could get them. I went back to the 95 tmk’s at 3660.

I ran them up to about 3750 in my 20” 6 saum. Not near as fast as I thought I could get them. I went back to the 95 tmk’s at 3660.

What is your load for the 95. I am getting a 18” 6-saum done for the 90 grain game changer and would like a idea of what powders are going to be best
Thanks