6.5 Creedmor - Palma style brass

[mRad]

The trick might be picking the right primer. When I did the .223 primer testing, I was shocked at how much different primers could impact the group size.

They really can. That’s why I advocate starting over if you switch them. You can end up way hotter for no reason other than a new primer. I’ve even seen lot to lot variance on the same primer make a load fall apart, relatively speaking of course.


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[T2C]

The trick might be picking the right primer. When I did the .223 primer testing, I was shocked at how much different primers could impact the group size.

What primers are you using for 6.5 Creedmoor loads? I am currently using Federal GMM 210M large rifle primers.

[markm]

Same here. 210M in the large primer. I'm suspicious of the BR-4s in small primer because they murdered my group size in .223.

[mRad]

BR-4s are great primers but you can’t substitute them with another. Gotta work up from scratch.

I’ve run them in four different rifles without ever having a problem finding a node. They are my go-to for small rifle primers.


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[T2C]

Same here. 210M in the large primer. I'm suspicious of the BR-4s in small primer because they murdered my group size in .223.

If we are using the same primers, I must be doing something else wrong. On the last trip to the range, I fired a 10 shot 2-1/4" group at 300 yards with hand loads. Hornady 120g Match printed a 13/16" group extreme spread.

[mRad]

If we are using the same primers, I must be doing something else wrong. On the last trip to the range, I fired a 10 shot 2-1/4" group at 300 yards with hand loads. Hornady 120g Match printed a 13/16" group extreme spread.

There is nothing wrong with your primers. It’s something else. How did you develop your load?


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[T2C]

There is nothing wrong with your primers. It’s something else. How did you develop your load?


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I used Barnes Match Burner 140g and Sierra 123g bullets with Varget, RL-16 and IMR 4350. I ladder tested the charge weights at 200 yards for optimum weights, then moved out to 300 yards and changed C.O.L. until I saw the tightest groups. Brass was neck sized and trimmed halfway between trim and maximum length. I started with the same bullet jump as Hornady factory ammunition and worked from that point.

The rifle shoots well with both Hornady 120g ELD Match and 140g ELD Match, so bullet weights between 120g and 140g should work. The 140g ELD will consistently shoot 1-1/2" groups at 300 yards with the 120g Match doing better.

[mRad]

Do you have H4350 available?

Why neck size?

How much did you adjust seating depths?

What sort of velocities, ES, and SD do you get?

What does your runout look like?


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[T2C]

Do you have H4350 available?

Why neck size?

How much did you adjust seating depths?

What sort of velocities, ES, and SD do you get?

What does your runout look like?


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H4350 is not available locally.

I neck size instead of full length size, because it has yielded the most consistency in my other bolt action rifles. I tried bumping the datum line back 0.002" with no change in results.

Seating depths were varied for 0.010" bullet jump out to 0.120" bullet jump. The Hornady factory ammunition bullet jump is 0.110" and it consistently shoots tight groups.

Velocities ran from 2,580 fps to 2,720 fps with 140g bullets and 2818 fps to 2932 fps with 123g bullets measured 15 feet from the muzzle.

The most consistent load had an Extreme Spread of 32 fps with Standard Deviation of 15 fps.

Run out is 0.0025"-0.0040" at the bullet ogive with anything over 0.005" being rejected.

When I shoot a 2-1/2" group at 300 yards with reloads, I immediately follow up with 10 rounds of factory ammunition to eliminate the possibility it's an equipment problem or I am having a bad day at the range.

I may try ladder testing loads with changes in the amount of crimp.

[mRad]

If you neck size how can that be more consistent? You have a different datum to ogive each firing. You have different lug pressure every time. Wouldn’t firing with them same shoulder bump every time be more consistent?

Check out Erik Cortina’s video on neck sizing.

Are you annealing?


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