6.5 Creedmoor load development

[beerbucksducks]

I tried my hand at the “10 round load development” for the first time today. I picked up a Bergara B14 hunter a few months back and cannot seem to get anything sub moa out of it out to 200. I have tried 140 ballistic tips and accubonds. Now I’m working with 130 accubonds. Tried H4350 and Varget. Now found some RE17 to work with. I am constantly getting 1.25” at 100 and 2.5” at 200 with most loads but I cannot seem to get it to group any tighter.

Since I found a pound of RL17 I decided to give the “10 round load development” a try. I loaded 15 rounds instead of ten, but worked up from 41-43.8 in .2 grain increments. Bullets were seated .100 off the lands. All loads were shot at 200 yards over my magnetospeed. I have attached the target, which doesn’t show much to my eye, and the velocities I gathered. If I am understanding correctly, I have a node or flat spot at 41.4-42. I would love some input from you guys on where to go from here. I am planning to work with seating depth and a load in the 41.6 range. There are a few spikes and drops in the velocities which I can’t explain. All powder charges were thrown on my Lyman powder dispenser and double checked on my beam scale.
Any advice on where to go from here is greatly appreciated! Thank you!

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[Dwh7271]

I wouldn’t go as high as 42.2, 42 looks like the top of that node.
Try some at 41.7. May just find some magic there.

 

[BigBza]

I tried the 10 load development from the 6.5 guys and had some challenges. It eventually took about 20 rounds to get to a velocity to test. After going on a Quick Load course I have found that I can get to a node with just three rounds, using Quick Load. What you need to get to is optimal barrel time. For a full explanation of this go to the-long-family.com and read up about barrel time.
http://the-long-family.com/optimal%20barrel%20time.htm

Do you have a fired case that you can use to get the fired case H2O weight in grains?
1. Weigh the empty case.
2. Fill the case with water drop and a tiny bit of washing liquid to break the surface tension.
3. The case must be completely filled with a flattish top.
4. Weigh the case and subtract the two weights.

Measure the barrel length to the bolt face.
1. Close the bolt
2. Gently slide a cleaning rod down the barrel
3. Mark the rod and then measure.

Once you have these two measurements we have some sample velocities, we can now accurately predict the barrel time load with QL. Once you have this you can then start playing with COAL.

Data needed is:
1. Case H2O mass
2. Barrel length
3. Temperature on the test day
4. Three velocities + powder weight
5. Bullet description
6. Caliber

With this data we can then give you a load that should work.



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[BigBza]

Apologies we also need the COAL not CBTO


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[BigBza]

I wouldn’t go as high as 42.2, 42 looks like the top of that node.
Try some at 41.7. May just find some magic there.

My previous post re the QL prediction will be useful should you want to use a different powder or want to get the next node without getting into dangerous loads. And we can fairly accurately predict the node with three measured velocities. Since you have already “got to a node” with testing you may as well continue.

From the data you have I would agree that
41.4 - 2756
41.6 - 2756
41.8 - 2760

These are very close together so load three (five if you don’t mind spending the extra) of 41.5; 41.6; and 41.7

Shoot those measure the velocity and check the targets for accuracy. What you want is the smallest SD and the lowest ES. You may just find that the load that gives you this is the most accurate.



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[mjcmichigan]

It’s possible you need to try a different primer. Maybe the CCI BR2
(If I have my numbers right, a bench rest large rifle.). I’ve seen those tighten up groups for some combinations.


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[frankm]

I concur with others good recommendations. I d try 41.7, or if you like one tenth of a grain on each side, and shoot those. I d go with Saami max OAL at this point to see if anything develops. I ve found in my 2 Creedmoors they seem to shoot well around 2.80-2.81.... I ve tried touching, back .010,.020,.030, etc and end up at 2.810. That's with Hornady AMax, ELD s...

Lastly consider another couple bullets if things don't come around. Sierras usually very forgiving on seating depth. Creedmoor isn't demanding on bullet construction due to its velocity range.

Keep us posted!

 

[beerbucksducks]

Thank you all for the input! I will run some test loads around 41.7 and see what develops. Switching primers is a good thought, as that is one element I have not changed. The longest COAL I can get to feed with my mag box is 2.836 which is .023 off the lands based on my measurements with the Sinclair oal gauge.


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[jimbires]

try finding your seating depth first , then work your powder . read my last two posts to this thread .


viewtopic.php?f=4&t=34035&start=75


I've never used a magneto speed chrony . I'm wondering if that attached to your barrel could be skewing the target .

 

[beerbucksducks]

I typically don’t shoot test targets with the magneto speed attached. I figured I might as well try it this go around since I was clocking loads anyway. But I have always had the same concern with the effects on barrel harmonics with the magneto attached. With that said, I will definitely be checking velocities and doing accuracy testing separately.


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[Dwh7271]

Once you have this you can then start playing with COAL.

Just be aware using OBT that the seating depth change is actually changing barrel time.

The magnetospeed does change poi when attached. I don’t notice a significant difference in group size just poi. Of course, when shooting only for velocities I don’t use a target as all I care about is getting the numbers.

There’s nothing wrong with any of the methods whether it’s OBT, OCW or the Ten Shot. They all will work with varying results. Having used all three I tend to use the ten shot method (although sometimes it’s fifteen :grin: ) as it is producing the best results for me. I went away from OBT, even though it does do fine, due to there being too many variables in the factoring. A lot of QL maneuvering to get there, which as you all know I really enjoy fooling with. You end up finding OBT and OCW with the ten shot method anyhow or darn close to where they are.

As mentioned above, if your SD and ES are low then you’re ready to stretch it out if that’s your gig. The ES being low will cut your vertical dispersion at longer distances. Factoring your SD, if you care to, will allow you to predict load viability and potential highs and lows of the load itself. 66% will fall within one standard deviation, 95% will fall within 2.

 

[trailboy68]

Interested, thanks

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[jimbires]

has , or is , this rifle able to shoot smaller groups ? is the scope , and mounts , tight ? is the scope good ? is the action screws tight ?

 

[Dwh7271]

Good points Jim

 

[beerbucksducks]

Scope and mounts are all good. I have one load that will do .75” at 100 but opens up at 200. Action screws are tight.


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[TackDriver284]

If RL-17 does not work for you, try H-4350, its a great powder.

 

[jimbires]

does the magazine box float ? when you drop open the floor plate the box should be able to easily move around a little .
have you tried the Hornady ELD bullets ? from what I read it seems like guys get good results with these in the 6.5 creedmoor with H4350 .


Mark , he said he has tried H4350 ( first post ) . I'm not sure if he's tried H4350 with this AccuBond bullet .

 

[TackDriver284]

Mark , he said he has tried H4350 ( first post ) . I'm not sure if he's tried H4350 with this AccuBond bullet .

Oh wow, I am getting old and missed that. Thanks for the heads up. :shock:

 

[beerbucksducks]

I have tried H4350 with both 140s and with the 130s. Eldx will be my last ditch effort before I send it back to checked out. I shot a box of the factory precision hunter load with eldx and it was 1.25-1.5 at 100 but have not tried loading them my self. Mag box will slide up and down a bit with floor plate dropped.


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[Cleveland48]

I had seen all the videos on YouTube about the B14 HMR being so accurate. So I talked my brother into buying it. I took the rifle home with me and started load work up after he did there version of a barrel break in. To my surprise it struggled to shoot just about anything under an inch. I believe it’s best was in the .9’s. This is factory loads and 123 scenars handloads. Off course I felt bad that he had spent the money on it cause of me. So I bedded the recoil lug with some JB weld and low and behold the same loads with scenars all grouped in the .6’s. And all the same factory loads were in the .7-.8’s. I know yours in the hunter but it is the exact same action as the HMR. I know it stinks having to work on a brand new gun, but it maybe be worth the time. Hope you get it sorted out!


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