Sierra Heavy TMK 6MM Testing

[mxgsfmdpx]

Assuming you are shooting the 115 bergers, what is your starting velocity and 750-800 velocity. That’s impressive! I have a 1:8 .243 and I’d like to get a little closer to this.


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Yeah the 115 Bergers actually give up a bit of “killing distance” compared to say, the 108 ELDMs on paper. Remember that the heavier bullet also slows down faster than a lighter one, and also slows down faster inside animals (all things being equal). Generally speaking, at most realistic hunting yardages, most are going to benefit from the speed of say a 95 TMK, over the heavier new 6mm TMKs (comparing two guns within the same chambering). Focusing solely on “how far my gun will kill” is easy to get caught up in.

My current 16” 6 creed 7.5 twist has finally stabilized with the 115s at right around 2,765-2795ish at the muzzle.

At my average hunting DA (say 50 degrees and 5,000 feet) that has it at roughly 1825ish FPS at 800 yards.

I do hunt at much higher and lower DAs so using the “mid DA” point as an “average”. Yes, DA plays a large role in how quickly a bullet slows down over distance in the air.

Folks get wrapped around the axle over BC and “how far my gun can kill” (I’m more guilty than anyone else), but in general, a good killing bullet like a 95 SST, 95 TMK, 103 ELDX, 108 ELDM from your 243 isn’t going to limit a hunter in the VAST majority of your killing situations and opportunities.

Plus it keeps folks a bit more honest as nearly nobody who hunts in the mountains is regularly practicing to make those types of shots at those yardages in unfamiliar terrain and conditions.

Anyway, carry on with the stuff everyone wants to see. I’ll keep watching from the side and try not to clutter anymore.

 

[Marbles]

Remember that the heavier bullet also slows down faster than a lighter one, and also slows down faster inside animals (all things being equal).

I think that is backwards. Heavier objects have more momentum and are more resistant to changes in direction or velocity.

As mass goes up, BC goes up. Make a lead core bullet and a solid copper bullet with identical external dimensions and the lead core bullet will have a higher BC and hold on to its velocity longer.

What has a longer stopping distance, an empty tanker truck or the one with 8000 pounds of water in its tank?

 

[mxgsfmdpx]

I think that is backwards. Heavier objects have more momentum and are more resistant to changes in direction or velocity.

As mass goes up, BC goes up. Make a lead core bullet and a solid copper bullet with identical external dimensions and the lead core bullet will have a higher BC and hold on to its velocity longer.

What has a longer stopping distance, an empty tanker truck or the one with 8000 pounds of water in its tank?

All things being equal (BC and weight) a topic for another place.

 

[CBB1]

Yeah the 115 Bergers actually give up a bit of “killing distance” compared to say, the 108 ELDMs on paper. Remember that the heavier bullet also slows down faster than a lighter one, and also slows down faster inside animals (all things being equal). Generally speaking, at most realistic hunting yardages, most are going to benefit from the speed of say a 95 TMK, over the heavier new 6mm TMKs (comparing two guns within the same chambering). Focusing solely on “how far my gun will kill” is easy to get caught up in.

My current 16” 6 creed 7.5 twist has finally stabilized with the 115s at right around 2,765-2795ish at the muzzle.

At my average hunting DA (say 50 degrees and 5,000 feet) that has it at roughly 1825ish FPS at 800 yards.

I do hunt at much higher and lower DAs so using the “mid DA” point as an “average”. Yes, DA plays a large role in how quickly a bullet slows down over distance in the air.

Folks get wrapped around the axle over BC and “how far my gun can kill” (I’m more guilty than anyone else), but in general, a good killing bullet like a 95 SST, 95 TMK, 103 ELDX, 108 ELDM from your 243 isn’t going to limit a hunter in the VAST majority of your killing situations and opportunities.

Plus it keeps folks a bit more honest as nearly nobody who hunts in the mountains is regularly practicing to make those types of shots at those yardages in unfamiliar terrain and conditions.

Anyway, carry on with the stuff everyone wants to see. I’ll keep watching from the side and try not to clutter anymore.

Thank you, sometimes I need to be reminded of that.


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[Speaks]

Yeah the 115 Bergers actually give up a bit of “killing distance” compared to say, the 108 ELDMs on paper. Remember that the heavier bullet also slows down faster than a lighter one, and also slows down faster inside animals (all things being equal). Generally speaking, at most realistic hunting yardages, most are going to benefit from the speed of say a 95 TMK, over the heavier new 6mm TMKs (comparing two guns within the same chambering). Focusing solely on “how far my gun will kill” is easy to get caught up in.

My current 16” 6 creed 7.5 twist has finally stabilized with the 115s at right around 2,765-2795ish at the muzzle.

At my average hunting DA (say 50 degrees and 5,000 feet) that has it at roughly 1825ish FPS at 800 yards.

I do hunt at much higher and lower DAs so using the “mid DA” point as an “average”. Yes, DA plays a large role in how quickly a bullet slows down over distance in the air.

Folks get wrapped around the axle over BC and “how far my gun can kill” (I’m more guilty than anyone else), but in general, a good killing bullet like a 95 SST, 95 TMK, 103 ELDX, 108 ELDM from your 243 isn’t going to limit a hunter in the VAST majority of your killing situations and opportunities.

Plus it keeps folks a bit more honest as nearly nobody who hunts in the mountains is regularly practicing to make those types of shots at those yardages in unfamiliar terrain and conditions.

Anyway, carry on with the stuff everyone wants to see. I’ll keep watching from the side and try not to clutter anymore.

Super good point. Have been kind of obsessing about what to shoot in my new 6cm but reality is that I have never shot at game over 250 yards and shot opportunities over 400 would be rare. It really does not matter and any decent killing bullet will do fine.

 

[Marbles]

All things being equal (BC and weight) a topic for another place.

But, if BC and weight are equal, you don't have a heavier bullet.

BC accounts for mass, so change mass and all things cannot be equal.

BC=mass/(cross-sectional diameter^2)(coefficient of form)

So, as mass goes up, BC goes up unless the diameter is increased (caliber) or the shape changed to be less aerodynamic. As BC goes up, velocity at range goes up, which is the opposite of slowing down faster.

Yeah the 115 Bergers actually give up a bit of “killing distance” compared to say, the 108 ELDMs on paper. Remember that the heavier bullet also slows down faster than a lighter one, and also slows down faster inside animals (all things being equal).

You said on paper, so while your experience in use absolutely trumps mine, and I am not making any argument on actual use, I can play on paper on an equal footing.

So, going back to the original 115 VLD vs 108 ELDM, assuming the same velocity of 2790 fps for both, a DA of 5000 feet, and using Applied Ballistics CDM drag model for both: The berger stays above 1800 fps out to 780 yards and the Hornady out to 720 yards. So, on paper, the heavier bullet doesn't give up anything in "killing distance" unless it also has a higher minimum expansion velocity. This also lines up with Hornady's listed G1 BC of 0.536 and Bergers listed G1 BC of 0.568.

If we apply the same, except change the 108 ELDM MV to 2890 (saying we can push the lighter bullet faster) it then holds above 1800 fps out to 780 yards, tying the Berger on "killing distance" on paper.

None of this is arguing that higher weight is better, it is trying to make sure that basic concepts are stated correctly. I am switching to the 95 TMK from the 108 ELDM because both hold above expansion velocity well past the range I should be shooting at animals at. I'm in agreement with your conclusion, it is a needless worry.

 

[mxgsfmdpx]

But, if BC and weight are equal, you don't have a heavier bullet.

BC accounts for mass, so change mass and all things cannot be equal.

BC=mass/(cross-sectional diameter^2)(coefficient of form)

So, as mass goes up, BC goes up unless the diameter is increased (caliber) or the shape changed to be less aerodynamic. As BC goes up, velocity at range goes up, which is the opposite of slowing down faster.



You said on paper, so while your experience in use absolutely trumps mine, and I am not making any argument on actual use, I can play on paper on an equal footing.

So, going back to the original 115 VLD vs 108 ELDM, assuming the same velocity of 2790 fps for both, a DA of 5000 feet, and using Applied Ballistics CDM drag model for both: The berger stays above 1800 fps out to 780 yards and the Hornady out to 720 yards. So, on paper, the heavier bullet doesn't give up anything in "killing distance" unless it also has a higher minimum expansion velocity. This also lines up with Hornady's listed G1 BC of 0.536 and Bergers listed G1 BC of 0.568.

If we apply the same, except change the 108 ELDM MV to 2890 (saying we can push the lighter bullet faster) it then holds above 1800 fps out to 780 yards, tying the Berger on "killing distance" on paper.

None of this is arguing that higher weight is better, it is trying to make sure that basic concepts are stated correctly. I am switching to the 95 TMK from the 108 ELDM because both hold above expansion velocity well past the range I should be shooting at animals at. I'm in agreement with your conclusion, it is a needless worry.

I think discussing elsewhere will help to not clutter the intent of this thread so I’ll be brief in what I was trying to convey (likely poorly).

Within the cartridge, in general, the lighter bullets going faster, at realistic hunting distances, can give them advantages as I stated. I’m not going to type out all the details on my phone and write a novel here, in what would be a simple conversation in real life haha.

Your example of 115 and 108 going the same speed is where the issue is. I stated the 108 on paper can “kill further” because with real world guns with real world known velocities from various cartridges, it maintains killing velocity beyond the 115. Because it leaves going faster. It’s nitpicking and isn’t “much” but it is what it is.

In what I’ve seen in gel at lower impact velocities, with bullets of near or exact construction, the heavier bullet loses momentum quicker and can penetrate less. This is usually more observed when increasing diameter and not length and isn’t always the case.

It seems you understand my intent based on your last couple sentences . This would be a neat discussion in another thread.

 

[RWT]

@Marbles & @mxgsfmdpx

It seems you understand my intent based on your last couple sentences . This would be a neat discussion in another thread.

Thank you both for being adults and cordial in this discussion. I learned something. Quite an enjoyable conversation. A shame we can’t do it in person over an adult beverage.

 

[wysongdog]

@Marbles & @mxgsfmdpx

Thank you both for being adults and cordial in this discussion. I learned something. Quite an enjoyable conversation. A shame we can’t do it in person over an adult beverage.

Agreed 100%. Guaranteed I would learn something and enjoy it

 

[waldo9190]

You bastards are going to make me buy a Tikka 243 aren't you?

 

[CBB1]

You bastards are going to make me buy a Tikka 243 aren't you?

You are being groomed…

Don’t worry, they got me 2 years ago, it ain’t all bad.


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[amassi]

You bastards are going to make me buy a Tikka 243 aren't you?

In for a penny, get that sako 90 over on Eurooptic


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[43.6N]

You bastards are going to make me buy a Tikka 243 aren't you?

Just a forum full of enablers.

 

[waldo9190]

Just a forum full of enablers.

Good thing for you guys is I'm a sucker for a little peer pressure.

 

[TBoschma]

No further explanation needed
View attachment 984974

I’m convinced

 

[letrbuck]

 

[PanhandlePilgrim]

Awesome stuff. I'm excited to see Sierra is getting their heads out of their asses. Their bullets have always shot great for me but none of their offerings seemed to be the standout answer for hunting. The TMKs are great, but the 95s were rarely available and the 195s in 30 cal just didn't compete with the BCs available from other companies. I have a tikka CTR that just might get a 6mm barrel next year... now I just have to decide what case head to go with.

 

[Jordan Smith]

In what I’ve seen in gel at lower impact velocities, with bullets of near or exact construction, the heavier bullet loses momentum quicker and can penetrate less. This is usually more observed when increasing diameter and not length and isn’t always the case.

Just one small point to add to this side tangent...

Assuming all else equal (including drag force on equal frontal surface areas), the heavier bullet penetrates further. Changing calibers muddies the waters by changing that drag force, and becomes an apples to oranges comparison that is not "all else equal."

 

[Jordan Smith]

These bullets just don't seem to be picky.

Shot 4x 10 shot groups today with a Seekins 6 Creed PH2, with around 1400 rounds on it. All three bullets, plus one got a second group which was seated deeper.

View attachment 985211

Individual groups were between .6's and .8's (MOA). All 40 rounds laid overtop each other were right at one MOA.

View attachment 985213


Next I did 6 groups with my Dasher, all three bullets at two seating depths. This is the barrel from my No Clean Dasher Test, you can look up how it typically shoots Berger 109's.

View attachment 985214

The groups ranged from .4's to .7's (MOA). All 60 rounds together were right at .9 MOA.

View attachment 985215

Finally I did three more groups with the Tikka, jumping further this time.

View attachment 985216

These were fine, although the one impact to the right on the middle group did make it the worst of the whole test. .9's, 1.4's, and 1.0's for those three.

This aggregate is less impressive, but it's still ~ 1.6 for 60 rounds over three bullets, two charge weights, two seating depths, and two days.

View attachment 985219

Had a fantastic day for testing here, was in a t-shirt most of the time.

View attachment 985220

View attachment 985221

Thanks for sharing those results, Carl! Awesome shooting and a couple of hummer barrels you've got there.

Super promising preliminary testing results for these new bullets!

 

[wind gypsy]

Notable from @Carl Ross 's results - if factory seekins and tikka barrels, they are at least grouping well with 8 twist barrels at whatever DA Carl had.