6mm creedmoor help

[Demikemoee]

Help, I started some load development with 90 grain eld-x and h4350. The rifle is a criterion remage barrel, 26”, 1:8 twist cut at .109 freebore. It’s once fired lapua brass, small rifle primer, full length sized with a s style Redding bushing with a SAC .269 bushing inside.



I did a jump test first finding the best accuracy with a mild load at .11 and .13 and settled in the middle with .124 with a CBTO of 1.944.



I then tried a ladder test with a magneto speed. I went 1.5 grains below max charge which was 45. So starting at 43.5 I increased by .3 ending at 45. I shot 2 rounds per charge single feeding each round.



So make a long story short I never found the flat spot but had very low es with certain charge weights.



43.5: 3359, 3355 (es 4)

43.8: 3363, 3404 (es 41)

44.1: 3405, 3397 (es 8

44.4: 3422, 3425 (es 3)

44.7: 3443, 3441 (es 2)

45: 3467, 3447 (es 20)



I went with the 44.7 being as it should the lowest es per 2 rounds. It shot an amazing group and had some excellent numbers with the first 10 rounds.



I went back and chronoed 28 rounds after and shot for groups and something has changed. I shot 4 5 shot groups and 1 three shot. 2 of the groups had good es of 16-19. The rest were 44-74.



So I obviously am not in the node? What should I do from here? I’m being as consistent as I can be with the tools I have available. So I don’t think it’s that. The only thing I changed between the 10 rounds too the 28 was I cleaned the carbon out the rifle.

 

[Feniks Technologies]

- there’s no such thing as a “velocity flat spot.” You don’t increase powder and not get more velocity. It’s just a product of variance when one round shoots on high side of ES and another on the low side of ES

- 2rnds means little to nothing except to eliminate “bad” performing loads. The “good” loads may very well be “bad” but just not the two shots you fired

- after cleaning carbon, you’ll need some fouler shots. They may or may not run at same speed as post foulers. Not a good idea to use them for data

- your real sd/es becomes very confident around 30 rounds. So the numbers you are seeing with the longer strings are more realistic.

- your experience is a common one. Low sample size shows something good and then it appears to “fall apart” once you shoot more. The fact is, it was always like that, I didn’t fall apart. You just shot enough to get the real story.

- consistent neck tension (not just interference fit….the whole of many parts related to the neck) and a consistent powder drop will have the most effect on chrono numbers.


So, explore your neck preparation and such. Try a mandrel if you don’t already. And get your powder drop as consistent as your scale will allow.

 

[jolofree]

What is your goal here, small groups on paper or hits on steel at distance, and at what range 500yd max, 1100 ?
Are you dead set on those 90gr bullets ?
Look at some of the 6CM loads posted on here, Might try Berger 105 jump 70 thou ~ 41-42gr 4350
GL

 

[Demikemoee]

What is your goal here, small groups on paper or hits on steel at distance, and at what range 500yd max, 1100 ?
Are you dead set on those 90gr bullets ?
Look at some of the 6CM loads posted on here, Might try Berger 105 jump 70 thou ~ 41-42gr 4350
GL

It’s a thermal coyote rifle. Max range would be 600-650. I’m new too some of this so excuse any ignorance. From what I have consumed, low ES consistent rifles don’t necessarily shoot one hole at 100 but maintain excellent vertical spread at distance. So my goal was to create an accurate load that produced low es to maintain consistency.

 

[ShtrRdy]

If you were shooting groups with the Magnetospeed attached the groups may not be good after you remove the Magnetospeed.

Was the once fired Lapua brass fired 8n the same rifle?

 

[Demikemoee]

If you were shooting groups with the Magnetospeed attached the groups may not be good after you remove the Magnetospeed.

Was the once fired Lapua brass fired 8n the same rifle?

Yes sir fired in the same rifle.

 

[Supersubes]

Where'd you get the load data? Even in a saami .183 freebore chamber, 44.7 gr with a 90 gr bullet is seriously hot.

 

[spife7980]

Maybe this is just me but I would ask: any pressure issues? Your starting load is what I would have considered my max.

 

[spife7980]

Where'd you get the load data? Even in a saami .183 freebore chamber, 44.7 gr with a 90 gr bullet is seriously hot.

Great minds think alike… and sometimes even at the same time lol

 

[Supersubes]

Great minds think alike… and sometimes even at the same time lol

I had to go double check my data but my warmish 87 vmax load is 42 gr rl16. Lol

 

[Alanh]

Ok glad I’m not the lonely one who was worried about pressure. My opinion for what it’s worth is to slow it down. Go backwards or start at say 40.5. You should find a node somewhere in the 40-42.5 range that will still be 2950-3050.

 

[Feniks Technologies]

It’s a thermal coyote rifle. Max range would be 600-650. I’m new too some of this so excuse any ignorance. From what I have consumed, low ES consistent rifles don’t necessarily shoot one hole at 100 but maintain excellent vertical spread at distance. So my goal was to create an accurate load that produced low es to maintain consistency.

FWIW, a 50es (3250 and 3300) is only a ~ 2” vertical @ 600yds.

ES doesn’t mean much inside 800yds for practical sized targets.

 

[jolofree]

It’s a thermal coyote rifle. Max range would be 600-650. I’m new too some of this so excuse any ignorance. From what I have consumed, low ES consistent rifles don’t necessarily shoot one hole at 100 but maintain excellent vertical spread at distance. So my goal was to create an accurate load that produced low es to maintain consistency.

600yd shot in the dark is a hell of a poke, sneak up or call them in closer & shoot them in the middle w/ a 75gr V-Max

 

[huntnh]

Ya I’m thinking that’s a seriously hot load I’m shooting a heavier 103 grain but I’m at 40.5 and still 3000fps with a 26 inch barrel. Why so hot?
Your barrel going to toast at 800 rds

 

[Demikemoee]

Where'd you get the load data? Even in a saami .183 freebore chamber, 44.7 gr with a 90 gr bullet is seriously hot.

Right out the hornady book.

 

[Supersubes]

Right out the hornady book.

They're using a chamber thats .075 longer than yours, and their starting charge was 39.1 gr.

 

[Demikemoee]

600yd shot in the dark is a hell of a poke, sneak up or call them in closer & shoot them in the middle w/ a 75gr V-Max

We kill 99 percent 100 yards and in. I just have an accurate mil reticle, I practice standing out too that distance on a smaller sized target, have a way of ranging um so it’s more of the idea of I could if I had too.

 

[Demikemoee]

They're using a chamber thats .075 longer than yours, and their starting charge was 39.1 gr.

So I should should bring my charge weight down. I didn’t know the free bore effected charge weight and pressure. This is my first rifle that wasn’t bought off the shelf.

I’ll go down in weight and see if I don’t see more consistency. I did another test today. I’ll post the results in a min.

 

[Supersubes]

So I should should bring my charge weight down. I didn’t know the free bore effected charge weight and pressure. This is my first rifle that wasn’t bought off the shelf.

I’ll go down in weight and see if I don’t see more consistency. I did another test today. I’ll post the results in a min.

Max charge minus 1.5 grains should never be a start imo. Yes, shortening freebore had a large effect on pressures.

 

[Demikemoee]

Max charge minus 1.5 grains should never be a start imo. Yes, shortening freebore had a large effect on pressures.

Ok, so where I sit right now, what should I do? I shot 8 charges this morning with a range of 43.9-44.6 increasing by .1 and 2 rounds per charge.

 

[Demikemoee]

Here is what I have so far. I shot 2 rounds per charge round Robin (1-8, 8-1) all over chrono. Charge weights of 43.9-44.6 and increased by .1.

43.9- 3397, 3377 Avg: 3387 es: 20 between the 2
44- ?, 3393 so no avg or es recorded
44.1- 3378, 3417 avg: 3387 es: 39 between the 2
44.2- 3390, 3384 avg: 3387 es: 6 between the 2
44.3- 3418, 3416 average 3417 es: 2 between the 2
44.4- 3407, 3406 avg: 3405 es of 1 between the 2
44.5- 3421, 3415 avg: 3418 es of 6 between the 2
44.6- 3435, 3435 es of 0

So if I break down the es from group to group.

Es of group 1 & 2: 6
Es of group 2 & 3: 4
Es of group 3&4: 10
Es of group 4 & 5: 30
Es of group 5 & 6: 12
Es of group 6 & 7: 13
Es of group 7 & 8: 17

So what I can’t understand is, the groups that had the lowest es from group too group had the highest es between the 2 charges. The ones that came in at the teens had the lowest es between the 2 rounds.

I feel like I’m not in the node at all and maybe should go down below those charge weights based off what I’m reading.

 

[spife7980]

I feel like I’m not in the node at all and maybe should go down below those charge weights based off what I’m reading.

Have you shot on paper at all?
Because what you’re doing is never going to tell you how well it’s shooting.
And yes, drop your charge weights and read this

Understanding Pressure :: Primal Rights, Inc

Reading pressure is a required skill that all shooters must have. Whether you are shooting factory ammunition or your own handloads, you absolutely must be able to detect and interpret pressure signs on your fired brass.

www.primalrights.com

 

[Gk2286]

I’m new to the 6cm world I’m going to start with shooting 103gr eldx bullets and h4350 what is a good load charge to start off with for load development? Thanks

 

[Supersubes]

I’m new to the 6cm world I’m going to start with shooting 103gr eldx bullets and h4350 what is a good load charge to start off with for load development? Thanks

Straight from hornady