New TMK announced

[207North]

Yeah and 30 shots per barrel is pretty gay.

I just shot enough to stabilize velocity, zero the rifle, and confirm drop.

 

[Treeman_MG]

Yeah and 30 shots per barrel is pretty ga

My 16” 6 Creed is a 700-800 yard killing gun depending on DA.

I don’t think folks realize not only their capabilities (lack of) or their guns capabilities (way further than their abilities).

There’s probably only a dozen or so folks on this site that should even be trying to kill past 800. Even though everyone thinks they are that guy, I’ve seen nothing but the opposite.

Exactly why my next re-barrel will be an 18"-20" 6cm, as cool as the 6UM is, and as much as I have tossed around 6-284 and 6prc. The creed is capable well beyond what my current abilities are. All the creeds really are the easy button.

 

[Marbles]

I have no business taking a field shot past 400 yards, so even in heavy sea level AK air a 6 creed/243 from a 16 inch barrel gets me comfortably past that range.

I would like to push that out to 500 yards, but in the training time budget I have opted for physical conditioning over shooting.

 

[grfox92]

Yeah and 30 shots per barrel is pretty gay.

What do you mean 30 shots per barrel?

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[mxgsfmdpx]

What do you mean 30 shots per barrel?

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A silly exaggeration on barrel life for that cartridge.

 

[grfox92]

A silly exaggeration on barrel life for that cartridge.

I thought so but I also paused to wonder of you start shooting the throat out and have to start load dev all over after 30 rounds .


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[mtnbound]

I have no business taking a field shot past 400 yards, so even in heavy sea level AK air a 6 creed/243 from a 16 inch barrel gets me comfortably past that range.

I would like to push that out to 500 yards, but in the training time budget I have opted for physical conditioning over shooting.

I agree 100 percent with your priority.

 

[HuntHarder]

I have no business taking a field shot past 400 yards, so even in heavy sea level AK air a 6 creed/243 from a 16 inch barrel gets me comfortably past that range.

I would like to push that out to 500 yards, but in the training time budget I have opted for physical conditioning over shooting.

I hear you on physical conditioning over shooting. Imo it is far over looked by most but can make a hunt vastly more enjoyable. I have put myself far past where I planned on going by wanting to see what was over the next ridge or hill more than once. Both my trips to AK proved to be exhausting to say the least. Hiking thru wet tundra tussocks with a load of meat on your back is the hardest thing I've done. Not all miles are created equal.

 

[Treeman_MG]

I agree 100 percent with your priori

I hear you on physical conditioning over shooting. Imo it is far over looked by most but can make a hunt vastly more enjoyable. I have put myself far past where I planned on going by wanting to see what was over the next ridge or hill more than once. Both my trips to AK proved to be exhausting to say the least. Hiking thru wet tundra tussocks with a load of meat on your back is the hardest thing I've done. Not all miles are created equal.

I was told by my transporter on my caribou hunt that 1 mile in the tundra/tussocks is equivalent to 5 miles just about anywhere else. Felt pretty true to me!

 

[mxgsfmdpx]

I was told by my transporter on my caribou hunt that 1 mile in the tundra/tussocks is equivalent to 5 miles just about anywhere else. Felt pretty true to me!

Cats claw, ocotillo, and choya make for hikes taking about twice as long as you’d think here in AZ.

I went in with that same mindset in Alaska hunting moose. It was more like 3-4 times as long for sure.

 

[mj23polaris]

[mention]Ryan Avery [/mention] or [mention]Formidilosus [/mention] you guys know BC of these new bullets by chance?


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[Formidilosus]

[mention]Ryan Avery [/mention] or [mention]Formidilosus [/mention] you guys know BC of these new bullets by chance?


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Thread 'Sierra Heavy TMK 6MM Testing'

Dec 12, 2025

Sierra sent us some 115,116, and 117 to test. We will post the results here. @Formidilosus @PathFinder @Carl Ross

• Ryan Avery
• Replies: 235
• Forum: Long Range Hunting

• 

 

[RockAndSage]

I have no business taking a field shot past 400 yards, so even in heavy sea level AK air a 6 creed/243 from a 16 inch barrel gets me comfortably past that range.

I would like to push that out to 500 yards, but in the training time budget I have opted for physical conditioning over shooting.

If everyone just did this, we'd all be far more consistent, better hunters.

 

[roosiebull]

Would it be fair to assume the 107 would fit in a 6arc AR platform but probably not the 115?

 

[KyleR1985]

Would it be fair to assume the 107 would fit in a 6arc AR platform but probably not the 115?

.55-.6” of the bullet will be in the case. Mouth of case to shoulder is .37”.

You’ll have a lot of bullet hanging into case capacity.

 

[43.6N]

I did a little math yesterday evening trying to come up with the likely ballistic coefficients for these new TMK.

BC is sectional density multiplied by its form factor.
Sierra has 2 lines of tipped bullets with similar form factors. The TMK line, with a generally better form factor. And the TGK line with a slightly lower form factor. Example: .264 130TMK with g1 bc of 0.518 vs 130 TGK with g1 bc of .510.

If only using the current TMK line, I didn’t have enough data to build a good model. So I also included the TGK line. As a result, these estimated BC values will likely be slightly low compared to what Sierra ultimately reports.

Final caveat, these are simply estimates. I have no first hand experience with these bullets, and no inside info from Sierra. I’m simply a guy with an Idaho public school education and a ti84 calculator. I just wanted to see where these new bullets are likely to end up ballistically, and thought others here might want to know the same!

First is the spreadsheet with the TMK and TGK bullets listed by caliber.
Next I sorted by sectional density.
You can see a clear trend in BC between bullets with similar sectional density. This trend is the bullets form factor, and can be used to estimate the BC for our new TMK line:
Also you’ll notice outliers in BC for the light for caliber 150gr 7mm and 120gr 6.5mm. This is where these bullets have departed from the form factor model due to their low weight.

The Green highlighted numbers are the new TMK bullets. And my estimated G1 BC is the far right column:



Finally, comparing my numbers to the BC numbers in the heavy TMK testing thread, it looks like my estimate is close at least for the 116 bullet. 0.595-0.600 seems to be what those guys have reported so far.

 

[Matt5266]

We must of went to different idaho public schools, because I only understood half of all that lol

 

[mtnwrunner]

We must of went to different idaho public schools, because I only understood half of all that lol

Well, at least his spelling is correct.

 

[mj23polaris]

I did a little math yesterday evening trying to come up with the likely ballistic coefficients for these new TMK.

BC is sectional density multiplied by its form factor.
Sierra has 2 lines of tipped bullets with similar form factors. The TMK line, with a generally better form factor. And the TGK line with a slightly lower form factor. Example: .264 130TMK with g1 bc of 0.518 vs 130 TGK with g1 bc of .510.

If only using the current TMK line, I didn’t have enough data to build a good model. So I also included the TGK line. As a result, these estimated BC values will likely be slightly low compared to what Sierra ultimately reports.

Final caveat, these are simply estimates. I have no first hand experience with these bullets, and no inside info from Sierra. I’m simply a guy with an Idaho public school education and a ti84 calculator. I just wanted to see where these new bullets are likely to end up ballistically, and thought others here might want to know the same!

First is the spreadsheet with the TMK and TGK bullets listed by caliber.View attachment 991922
Next I sorted by sectional density.
You can see a clear trend in BC between bullets with similar sectional density. This trend is the bullets form factor, and can be used to estimate the BC for our new TMK line:
Also you’ll notice outliers in BC for the light for caliber 150gr 7mm and 120gr 6.5mm. This is where these bullets have departed from the form factor model due to their low weight.

The Green highlighted numbers are the new TMK bullets. And my estimated G1 BC is the far right column:

View attachment 991923

Finally, comparing my numbers to the BC numbers in the heavy TMK testing thread, it looks like my estimate is close at least for the 116 bullet. 0.595-0.600 seems to be what those guys have reported so far.

I hope the numbers for the .264 bullets are better than your calculations. Knowing what I know with personal experience with 147 eld and 153 Berger and what a good friend has seen with the 150 match kings. The new tmks need to be in my opinion .330+ G7. I’m coming at this from a competitive mindset. For shooting animals to me bc isn’t a main concern.

Like I’ve seen the 150 match kings true out at a .350 g7 the new tmk should be on par with a Berger 153. I’ve trued that out at box BC of .356.

Where i hope sierra pulls through is the 147. I’ve seen eld M 147s true out at a .311 and .330 with different barrels with an advertised BC of .351. So if they can make a consistent 147 that kills with a high bc it’ll be a winner over the eld m.


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[43.6N]

I hope the numbers for the .264 bullets are better than your calculations. Knowing what I know with personal experience with 147 eld and 153 Berger and what a good friend has seen with the 150 match kings. The new tmks need to be in my opinion .330+ G7. I’m coming at this from a competitive mindset. For shooting animals to me bc isn’t a main concern.

Like I’ve seen the 150 match kings true out at a .350 g7 the new tmk should be on par with a Berger 153. I’ve trued that out at box BC of .356.

Where i hope sierra pulls through is the 147. I’ve seen eld M 147s true out at a .311 and .330 with different barrels with an advertised BC of .351. So if they can make a consistent 147 that kills with a high bc it’ll be a winner over the eld m.


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I agree in principle, that more BC =More good.
But the more I shoot, the happier I am with truly consistent BC. As long as the BC is good enough, and I can trust it no matter the conditions, I can compensate for any wind number or trajectory. And I don’t think I’m alone with this line of thinking.

Example: Hornady has class leading BC. (Not knocking H, just an example) They have a form factor figured out that is very efficient. And that number moves a lot of bullets in the minds of consumers. And most of the time that extreme form factor flies well. But when the rubber meets the road in the competition circles, Berger wins out. The flight consistency (and underground marketing of Mr Litz’s work) has born itself out to the point that Berger becomes the default choice for exceedingly consistent bullets.

The crux for Sierra will be if they can keep the flight consistency that the lighter weight TMK’s have.