6 CM & 108 ELD Velocity - Barrel Length

[ljalberta]

I’m looking to put together a new Tikka 6 Creedmoor rifle. Ideally this will be through Unknown Munitions. I’ve been digging the Shoot2Hunt podcast and the fact they’re bringing some new stock designs to market

I can’t run a suppressor in Canada (because they’re too scary of course), but I still would like to keep the barrel on the shorter side.

Looking at the 108 ELDs (or 109s if they ever sold them up here), is 3000fps a realistic velocity from a 20” barrel? I have a significant supply of Varget and H4350 which look good on paper, but I’m trying to figure out realistic expectations.

As a bonus question, anyone have any strong opinions when it comes to carbon barrels and Benchmark vs Carbon Six vs Proof? This will be my first foray into a carbon barrelled rifle.

Thanks all,

 

[DJL2]

How hot do you want to load? My 26" Bartlein runs factory 108 ELD-M at right about 2950 fps... like it says on the box.

Let's assume my barrel is slow, and most 24" tubes will run that 2950 fps... and you lose 25 fps per inch... you'd be at 2850 fps for the factory load from a 20" barrel. If you want another 150 fps, you're gonna need to run it on the hot side.

QuickLoad indicates you're not getting there at less than 70 ksi using H4350 or StaBall. I didn't try GRT.

 

[Sadler]

My 16” carbon six barrel is shooting factory 108 eldm’s at 2660.

 

[Weldor]

My Seekins Element 21" suppressed with Hornady factory ELD-X 103 gr. is 2883 from my Labradar.

 

[ljalberta]

Thanks gentleman. It’s looks like it would have to be a real spicy load and I may have to temper my expectations or add some inches to the barrel.

 

[khuber84]

22" ruger predator, 2880 with supressor, shoots great, not great with no can.

 

[ljalberta]

it’s interesting that in this article, https://rifleshooter.com/2017/01/6-creedmoor-barrel-length-versus-muzzle-velocity-31-to-17-inches/ they were getting 3000 fps from a 107 SMK.

Any thoughts on Is this just because the difference in design of the 107 SMK, or the added powder from the ability to hand load?

 

[JollyRoger]

I have a Tikka 6CM with a 20” Bartlein barrel. With factory 108 ELD-M I’m getting 2869 based on real world drop data out to 1300yards.

 

[khuber84]

it’s interesting that in this article, https://rifleshooter.com/2017/01/6-creedmoor-barrel-length-versus-muzzle-velocity-31-to-17-inches/ they were getting 3000 fps from a 107 SMK.

Any thoughts on Is this just because the difference in design of the 107 SMK, or the added powder from the ability to hand load?

107smk is a different bullet dimensionally VS the 108eldm, way less bearing surface. I bet the same load with a 107 VS a 108 would be 40-60fps difference.

 

[DJL2]

I didn't answer the "bonus" part of your question - the only two CF wrapped barrels I have experience with are Proof and Bartlein. The Bartlein was on an M70 project gun that I've sold, the Proof is on a 6.5 CM "carbine" with a 20" barrel. The average five shot group from that rifle is ~.65 inches. As you might expect, the average 10 shot group (mind you, I haven't fired as many of these) is ~.9 inches. That's with either my 130 TMK hand loads (somewhat spicy at 2800+ fps) and factory loaded Hornady 140 ELD-M (at a far more sedate 2625 fps or so).

 

[Jimbee]

2899fps with a 19" Preferred prefit and reloads.

 

[khuber84]

I’m looking to put together a new Tikka 6 Creedmoor rifle. Ideally this will be through Unknown Munitions. I’ve been digging the Shoot2Hunt podcast and the fact they’re bringing some new stock designs to market

I can’t run a suppressor in Canada (because they’re too scary of course), but I still would like to keep the barrel on the shorter side.

Looking at the 108 ELDs (or 109s if they ever sold them up here), is 3000fps a realistic velocity from a 20” barrel? I have a significant supply of Varget and H4350 which look good on paper, but I’m trying to figure out realistic expectations.

As a bonus question, anyone have any strong opinions when it comes to carbon barrels and Benchmark vs Carbon Six vs Proof? This will be my first foray into a carbon barrelled rifle.

Thanks all,

I have negative opinions with carbon barrels in general. They're are definitely more picky and less forgiving than traditional steel. A fluted #5 or light palma on a Tikka tenon will weigh near the same possibly less than a carbon of 20". 3000fps is possible with hand loads. Run lapua srp brass and it'll take the psi, however I bet it'll be more happy at 2950.

 

[wind gypsy]

I’m looking to put together a new Tikka 6 Creedmoor rifle. Ideally this will be through Unknown Munitions. I’ve been digging the Shoot2Hunt podcast and the fact they’re bringing some new stock designs to market

I can’t run a suppressor in Canada (because they’re too scary of course), but I still would like to keep the barrel on the shorter side.

Looking at the 108 ELDs (or 109s if they ever sold them up here), is 3000fps a realistic velocity from a 20” barrel? I have a significant supply of Varget and H4350 which look good on paper, but I’m trying to figure out realistic expectations.

As a bonus question, anyone have any strong opinions when it comes to carbon barrels and Benchmark vs Carbon Six vs Proof? This will be my first foray into a carbon barrelled rifle.

Thanks all,

I'd not go into it expecting to run 108s @ 3000 FPS with a 20" barrel and H4350. I wont say you couldn't load it hot enough to get there but you'd will be well over max on any published data and SAAMI max pressure IMO. If 3000 FPS is important to you, I'd go at least 22" which would still be pretty handy without a suppressor.

RL26 would certainly help if it's velocity you seek. I've got a bunch of it but haven't brought myself to use it over H4350. Varget is pretty dang fast burning for a 6 creed and heavies.

Here’s results from a 1 shot ladder from 18” w/ suppressor. Primers a little flatter at top load but no other concerning signs:

 

[PantherCity]

I’m getting 2900 from a 20” preferred prefit
108 eldm lapua SP & H4350

Buddy has a 22” prefered and is getting 3000 with 115 dtacs and same components


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[khuber84]

My shorty 6cm experience:
I have an 18" 7.5tw short freebore on a Tikka, running 105hyb at 2950 with 42.6gr H4350, I guarantee this load is north of 60k psi, probably closer to 70k, but I don't have bolt lift or ejector marks, I'd probably not run this year round., it also shoots 95tmk very well round 3050-3070fps.

 

[Reburn]

20"
1:7.5
108 eld-m
2908 fps

 

[ljalberta]

Much appreciated to everyone for their input. I think I will still proceed with a 20” barrel 7.5 twist and aim for 2900 fps. At my most common hunting altitudes (2000’-9000’), this gets me plenty of distance beyond what I’m capable of (with the aim to build out that capacity over the next couple of years).

 

[HankBC]

Much appreciated to everyone for their input. I think I will still proceed with a 20” barrel 7.5 twist and aim for 2900 fps. At my most common hunting altitudes (2000’-9000’), this gets me plenty of distance beyond what I’m capable of (with the aim to build out that capacity over the next couple of years).

How did this turn out for you? I’m in your neighboring province and was looking a similar direction for the next rifle build. I couldn’t find a reasonable way to get a rifle up here from unknown, so I bought the rokstock and they’re shipping it up for a flat $50.

Thinking 22” ibi barrel, Ti3 action, trigger tech diamond and m5 hunter dbm. Should be a good sheep / md rig.


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[Wyo_hntr]

My 24" proof research steel barrel was right at 3k fps from factory 108eldm

 

[ljalberta]

How did this turn out for you? I’m in your neighboring province and was looking a similar direction for the next rifle build. I couldn’t find a reasonable way to get a rifle up here from unknown, so I bought the rokstock and they’re shipping it up for a flat $50.

Thinking 22” ibi barrel, Ti3 action, trigger tech diamond and m5 hunter dbm. Should be a good sheep / md rig.


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This particular rifle is still being built by UM. I think it’ll be late spring to finish.