108 ELDM, 103 ELD-X, H4895, LeveRevolution

[Hurley88]

Hi, 

Just wanted to share some initial info I gathered on my recent 6 ARC build (Tikk T3X, posted about it under the bolt action section). 

Tikka T3X bolt action
Garmin Xero Chronograph
Starline 6mm ARC brass
Hornady 108 ELDM 
Hodgdon H4895

• 25.0 H4895: 2447.4 
  
  
• 25.5 H4895: 2516.5 
  
  
• 26.0 H4895: 2560.8 
  
  
• 26.5 H4895: 2603.8 
  
  
• 27.0 H4895: 2653.0
  

I also chronographed five shots of the Hornady 108 ELDM Match ammo: 

• Factory ammo: 2668, 2625, 2655, 2638, 2636. 
  
  
• Avg 2644 
  
  
• ES 43
  
  

I’ve sent the barrel off to be throated (I’ll post more as to why on the rifle build thread), so more info to come. The thread title shows what info I plan to collect & post.

[corpsman8483]

Nice; I have some of the ELDMs and H4895, I'll give it a try.

[Hurley88]

Forgot to mention, this is a 22” barrel. Honestly the whole reason I even built this rifle was bc I had 10lbs of H4895 and no purpose for it. Was for a rifle that has since gone on to a new home, so I hope the powder works well in dispersion testing.

We’ll see. I’ll post the results, good bad or ugly.

[Ray R]

Hi, 

Just wanted to share some initial info I gathered on my recent 6 ARC build (Tikk T3X, posted about it under the bolt action section). 

Tikka T3X bolt action
Garmin Xero Chronograph
Starline 6mm ARC brass
Hornady 108 ELDM 
Hodgdon H4895

• 25.0 H4895: 2447.4 
  
  
• 25.5 H4895: 2516.5 
  
  
• 26.0 H4895: 2560.8 
  
  
• 26.5 H4895: 2603.8 
  
  
• 27.0 H4895: 2653.0
  

I also chronographed five shots of the Hornady 108 ELDM Match ammo: 

• Factory ammo: 2668, 2625, 2655, 2638, 2636. 
  
  
• Avg 2644 
  
  
• ES 43
  
  

I’ve sent the barrel off to be throated (I’ll post more as to why on the rifle build thread), so more info to come. The thread title shows what info I plan to collect & post.


I shoot the 6mm ARC 105 gr. BTHP using 26.8 grains of RL-15 ==> 2607 fps and sub-MOA groups at 100 yards. I use a bolt Action Savage Axis II w/22" barrel. COAL=2.220"

Information from Quick Load software.

[Hurley88]

As promised…

Tikk T3X bolt action
Garmin Xero Chronograph
Starline 6mm ARC brass

Barrel has now been throated. Lowest point of the bullet is seated just below the case neck/shoulder junction, COAL 2.3065, CBTO 1.8135”. At that length, bullet jump is 0.060”.

Factory Hornady Match ammo, 108 ELDM:
2604.7
2580.5
2564.9
2597.9
2577.9
These factory rounds are now jumping 0.124” and were originally jumping 0.006”, so the slight drop in velocity is to be expected. Also it was about 20 degrees colder than last time. Small sample set, but there it is.

27.0gr H4895 under a 108 ELDM with 0.060” bullet jump:
2619.8
2624.8
2627.1
2627.6
2651.6
2624.0
2632.5
2619.0
2638.2
2639.6
Avg 2630.4, ES 32.2, SD 9.6

---

And more…

29.0 Lever, 108 ELDM: 2620.9
29.5 Lever, 108 ELDM: 2682.7
30.0 Lever, 108 ELDM: 2731.0
30.5 Lever, 108 ELDM: 2768.2
31.0 Lever, 108 ELDM: 2790.8

25.0 H4895, 103 ELD-X: 2448.4
25.5 H4895, 103 ELD-X: 2497.0
26.0 H4895, 103 ELD-X: 2548.3
26.5 H4895, 103 ELD-X: 2609.2

28.5 Lever, 103 ELD-X: 2616.1
29.0 Lever, 103 ELD-X: 2656.0
29.5 Lever, 103 ELD-X: 2710.9
30.0 Lever, 103 ELD-X: 2753.7
30.5 Lever, 103 ELD-X: 2803.4

---

Next up is a 10-shot group with each of these four combinations. If I can ever break free. Heavy work load, hunting season, other projects…hard to nail down time for this build.

[Hurley88]

More data, ten shots each:

Factory Hornady Match 108 ELDM
Avg 2626, ES 25.9

27.0 H4895, 103 ELD-X
Avg 2688, ES 25.9

29.5 LeverEvolution, 108 ELDM
Avg 2696, ES 20.3

29.5 LeverEvolution, 103 ELD-X
Avg 2722, ES 24.3

[Rickhem]

Lots of good data, how are your loads grouping for you? I have found that sometimes my lowest SD loads are not always the ones that group the best.

And having 10 pounds of H4895 is pretty amazing these days. I have been actively looking for that powder for well over a year, nearing two, and it just isn't around. Good for you having that big of a reserve.

[Hurley88]

Oh I used to go through a couple 8lb jugs a year lol. If you want it we can get in touch, I’ll likely be going with LeverEvolution for this build. Never shipped anything Hazmat, so that’ll be new.

Unless I’m shooting three ten shot groups for an average and as a composite to proof test after load dev, I ignore SD. How can you establish a standard deviation from the norm without enough data to establish a norm? That said, when shooting 100yd groups you’re correct the ES/SD numbers wont really correlate to group size, they have more to do with dispersion at longer distances. I do always pay attention to ES, as it is useful in establishing a general consistency level to compare between loads. As they were in this case, because they are what caused me to find my accuracy issue. Well…remains to be seen. But they’re what kept me from tossing the barrel in a trash bin.

The groups are all abysmal. Both before and after throating. The best 10-shot group is 1.4”, the worst 2.5”. The consistent velocity spread got me to consider the crown, because it seemed likely that with consistent velocities something must be smacking them upon exiting the barrel. I found a raised ridge around the last half inch of the barrel near the muzzle, the guy I go to when I have barrels chambered/contoured confirmed the ridge, then told me that it’s common to crown first then use a tool to center the barrel when chambering which causes that raised ridge. He said it happens with $500 prefits every now and again. Which is fine this is my 7th cheapo & the first I’ve had any issues with. So I’m chopping off the last inch and revisiting. Dunno if that’s true, I’ve never worked in a barrel factory, but we’ll see.