Not enough powder or?

[RubiconJoey]

I've been shooting a load for 6.5 Creedmoor and getting great groups. However since getting a Garmin chronograph, I've noticed I'm getting high ES and SD. In the last couple loadings I've also noticed soot on the cases (see photo below).

I first thought it might be my rifle but, the same load in my new rifle produced the same results. Same load/same exact cases with shoulder bump adjusted for the new rifle. The new rifle conveniently has a shorter chamber.

I then thought it might be the primer since I was using a standard small rifle primer instead of a magnum. I tried the same load with magnum primers and it made no difference.

Now I'm wondering if my powder charge is just too light? It would seem to make sense that if the powder charge was too light, the cases wouldn't expand enough to seal in the chamber causing the soot and high variation in velocity.

My load:
6.5 Creed Lapua SRP Brass (cases on 5th firing)
CCI #450Primer and #400 (I've tried both)
38.5gr Hodgdon H4350
Berger 130gr Hybrid OTM

My process:
Deprime using Lee universal decapping die
Dry tumble with rice
Anneal with AMP (0162 Aztec Code)
Lube cases with Hornady one shot
Size using SAC bushing die (.288 bushing)
Prime using Frankford hand primer (0.002 crush)
Dispense powder with AutoTrickler V4 and Super Trickler (I've tried both)
Seat bullets with SAC bullet seating die (max magazine length)

Is my powder charge too light or is something else wrong here? Berger suggest a starting load of 37.5 with a velocity of ~2470 FPS. In the photos below you'll see I'm getting an average of 2497.7 FPS with an SD of 12.6 and ES of 40.5. The case shows the soot I mentioned earlier (good amount in the extractor groove somehow). The primers look great with no signs or pressure.

 

[joshb]

Seems pretty slow to me. I don’t have my books in front of me and my memory can’t be trusted. My instinct says you should be throwing that bullet a lot faster. 28-2900 fps?
I’d increase charge weight in .3 grain increments up to pressure signs and see if you find a faster node.
Lots of guys swear by H4831sc. Might be worth a try, too.
That group looks good. You banging away at 100 yards?

 

[RubiconJoey]

Seems pretty slow to me. I don’t have my books in front of me and my memory can’t be trusted. My instinct says you should be throwing that bullet a lot faster. 28-2900 fps?
I’d increase charge weight in .3 grain increments up to pressure signs and see if you find a faster node.
Lots of guys swear by H4831sc. Might be worth a try, too.
That group looks good. You banging away at 100 yards?

Berger says max load is 41.6 at 2727 fps, so I'm definitely on the slow end. I had done a powder charge ladder when I first started working on this load and found this to shoot the best. However, the shooting Chrony I had at the time was inconsistent at best and I was only shooting 3-5 shots of each powder charge so the velocity variation went unnoticed. Yup, that group was at 100 yards.

 

[ShtrRdy]

I had a problem like this that was fixed by annealing the brass. Those were Lapua brass too.

According to SAAMI a130 gr bullet out of a 6.5 Creedmoor should be about 2900 fps

 

[J.D.Erwin]

my 6.5 load for the 130s and 140s is H 4350 41.2 grs and 43.9 grs of H4831sc avg fps with the 4350 is 2880 and 4831 is 2930

 

[joshb]

I’m stuck shooting at 100 yards, most of the time, so I shoot most of my guns in the lower nodes. It’s easier on my brass and I save a little powder.

 

[RubiconJoey]

I’m stuck shooting at 100 yards, most of the time, so I shoot most of my guns in the lower nodes. It’s easier on my brass and I save a little powder.

I had similar thoughts when I decided to run the 38.5 gr. My range is limited to 300, so I rarely get the chance to shoot beyond that.

 

[joshb]

You should try some lighter bullets then. Maybe even some 90s? 95s? and save those 130s for 300 yards. That’s what I do. I have a ton of Sierra 120s I got for cheap. They do pretty good at 100. I shoot my Berger 130s when I get a chance to shoot my 6.5x47 at 500.

 

[joshb]

I have a ton of Sierra 168 and 125s in 30 caliber. I shoot a lot of the 125s at 100.

 

[Peterson1]

Check your shoulder bumping while resizing
Only bump it back 0.0005 ----0.001 (For a bolt gun)
Just another thought

 

[RubiconJoey]

Check your shoulder bumping while resizing
Only bump it back 0.0005 ----0.001 (For a bolt gun)
Just another thought

I'm bumping back .002", both rifles are bolt guns.

The old rifle has a slightly longer chamber. The rounds I had sized for the old rifle require a little bit of force to close the bolt in the new rifle. I figure those would be slightly compressed (maybe 0.001") in the new rifle. I shot a few of them and results were essentially the same.

 

[Andy Work]

Not tumbling the brass and leaving the carbon in the necks may lower the ES.

 

[6BRA]

As a comparison, I ran 130s out of a 6.5x47 at 2950....all year long. Sounds slow...I know a guy with a 6.5 creed running 140s over 2800...

 

[Coyotefurharvester]

Are you bumping back because of bolt close effort? Clean up some brass with 0000 steel wool, load up some heavier powder charge test rounds. See if the soot and vertical dispersion changes ALONG with dropping/reducing your velocity spikes. If it doesn't you can always go back, or realize it probably doesn't matter much at shorter distances.

 

[RubiconJoey]

Are you bumping back because of bolt close effort? Clean up some brass with 0000 steel wool, load up some heavier powder charge test rounds. See if the soot and vertical dispersion changes ALONG with dropping/reducing your velocity spikes. If it doesn't you can always go back, or realize it probably doesn't matter much at shorter distances.

No, the only abnormal bolt effort I've had is from running the rounds sized for my old rifle in my new rifle. The plan is to try heavier powder charges but wanted to post here to make sure I wasn't doing something stupid. Haha

 

[D-4297]

Even if you are annealing after every firing , it usually take two or three firings in a "new" chamber to "reseat" your brass . Sometimes Shoulder diameter is slightly smaller from the old chamber compared to the new chamber , thus allowing the "leak" . And using a slightly above starting load isn't helping to seal the Brass to the chamber .
Just got done breaking in a new .308 Barrel , and used 190gr Sierra's with a 75% Max load to insure Brass would re-set to the New TR Chamber .

 

[DShortt]

How many cycles on the brass and have you been annealing?
It's quite possible that is what is causing the soot.

 

[jxb]

Given you're pushing 130's, I'd say low unless that's a super short barrel. But if it's the same load you where using when you were not having this issue, then that's not the cause. Certainly agree based on the brass you're not sealing up.

If those were 143gr you'd be two nodes below factory Norma match, which is ~2630 in my 23.5" barrel. I run my 143's one node above factory and it's still well below pressure.

 

[markm87]

Agreed. I use a notably higher charge for even heavier bullets. 140s going 2700

 

[RabbitSlayer]

If your sizing die deprimes I would anneal, lube, size, tumble. Or deprime before annealing if your die doesn't also punch the primer. Don't know that it will change anything, but that seems to be the order of operations most recommended.

I think more powder might help by filling more of the case.

Finally, I think many people are discovering their es\sd is higher than they thought and there is a bunch of internet BS from small samples. Now with the garmin, many people are putting every single shot over the chrono instead of 5 or 10. I put 95 shots over the garmin with an older load last weekend. The ES tripled compared to the 10 shots of data I had from the magnetospeed.