Sierra Heavy TMK 6MM Testing

[Hurley88]

What is the fastest MV loaded with a heavy 6mm bullet like the 108eld, 115dtac, or these new Sierra 107/116TMK (a reliable and accurate load) has anyone found for a 16" 6mmARC? Is 2550-2600fps unrealistic?

Yeah…gonna be stuck with CFE223 & Lever but it’s doable. Max loads of H4895 might get you around 2575, max loads of Varget a bit less. Loaded to bolt action pressures. If a gas gun I wouldn’t know off the top of my head.

That’s with 103 ELD-X or 108 ELDM. Don’t know about anything heavier.

 

[mudslinger021485]

First 5 shots with the 116’s avg 2700 fps. 18 inch 6 creed 1-7.5 twist.

What's that loaner under the bullseye all about?

 

[Spartan1810]

What's that loaner under the bullseye all about?

I’m just not that good man.

 

[Plague]

Thatsalotta lever!

What’s your OAL?

I like to party. I’ve got 1.751 CBTO and 2.392 COAL in the load notes on my phone.

 

[mudslinger021485]

I’m just not that good man.

Lol. I didn't mean to sound sarcastic that time. I'm legit curious if it was a flyer or intentional after a zero adjustment.

I had a group do the exact same thing yesterday. 2nd shot was off from the group. Idk if it was me or the junk barrel lol.

 

[huntnful]

Lol. I didn't mean to sound sarcastic that time. I'm legit curious if it was a flyer or intentional after a zero adjustment.

I had a group do the exact same thing yesterday. 2nd shot was off from the group. Idk if it was me or the junk barrel lol.

That’s just normal. “Flyer’s” just outside the main cluster are just your group showing you how it actually shoots without cherry picking or blaming random stuff. Accept it and life gets easier lol

 

[Treelineasassin]

I'm going to load up some the 107s for my 21in 7.5tw 6gt this week and get testing them. Will prob start 60k off and work up with rl15.5, rl16 and maybe H4350. Wont have my 116s till early April, those will all get set aside for the 6SAW.

 

[mudslinger021485]

That’s just normal. “Flyer’s” just outside the main cluster are just your group showing you how it actually shoots without cherry picking or blaming random stuff. Accept it and life gets easier lol

Lol

 

[Spartan1810]

Lol. I didn't mean to sound sarcastic that time. I'm legit curious if it was a flyer or intentional after a zero adjustment.

I had a group do the exact same thing yesterday. 2nd shot was off from the group. Idk if it was me or the junk barrel lol.

It’s just part of the group. I’ll shoot another 15-20 on that circle for reference. If you shoot large sample sizes…it gives a more accurate representation of the group as it pertains to the rifle, ammunition, and shooter.

 

[mudslinger021485]

It’s just part of the group. I’ll shoot another 15-20 on that circle for reference. If you shoot large sample sizes…it gives a more accurate representation of the group as it pertains to the rifle, ammunition, and shooter.

Oh I agree. The barrel I'm working with is a 6.5 and it wont shoot anything consistently from one minute to the next.

 

[shayes11]

107 tmk with 31gr of Lever in my Howa 6arc 20" mini got me 2820 which was pretty surprising. Also in the same hole. 30.5gr was a much more consistent load and just as accurate at 2770. Going to load 10 each and let the groups decide. All that to say I am very impressed compared to the 95tmk. Way less finicky.

 

[Treelineasassin]

I really wonder what the chamber pressure is on these 6arc loads pushing creed speeds. That has to be spicy!

 

[Plague]

I really wonder what the chamber pressure is on these 6arc loads pushing creed speeds. That has to be spicy!

No pressure signs for me with virgin Hornady brass and 31.5 gr of lever at 50ish degrees ambient temp. Need to chrono the load still. Guessing I’ll probably see some shooting this load come summer time.

 

[shayes11]

No pressure for me either. Im shooting factory 108s (which is loaded at gas gun pressure) at 2620. I dont think 150-200fps more seems that crazy. Admittedly this is only my 4th rifle work up but I have definitely messed around and experienced high pressure with a 28nos accidentally. I dont feel like I'm pushing that limit yet and don't plan too.

 

[Bluefish]

I really wonder what the chamber pressure is on these 6arc loads pushing creed speeds. That has to be spicy!

31.2 is book max for Hornady 108 data, 2850 for speed. I think the 107’s should be slightly less pressure. Doesn’t look like crazy data to me. There is a big difference from 6 arc gas to bolt speeds due to 2 things, 1) more pressure, 2) longer barrel. The bolt barrel length is 24” vs 18” for gas data. I think that 6” does more for speed than the pressure.

 

[Treelineasassin]

31.2 is book max for Hornady 108 data, 2850 for speed. I think the 107’s should be slightly less pressure. Doesn’t look like crazy data to me. There is a big difference from 6 arc gas to bolt speeds due to 2 things, 1) more pressure, 2) longer barrel. The bolt barrel length is 24” vs 18” for gas data. I think that 6” does more for speed than the pressure.

Everyones data is different. Sierra has max of 29.6gr cfe223 with a 107. 2800 from a 24in. Nobody here is shooting a 24in barrel either.

 

[Hurley88]

When I did a velocity snapshot with Lever in my 20” 6ARC with 108 ELDM about a year ago I broke 2800fps at around 30.5 grains as well. Think I remember noticing increased muzzle blast right at 30.5 & 31.0, I can look at my notes once home.

Given the increased blast and the fact that it’s a temp sensitive powder, I capped it at 30gr for my uses. Never settled on a load above 29.5 afterwards.