Thread: High Pressure signs?

I will really appreciate some advice and feedback:

Last week I did my first ever reloads. I prepared two load development sets for my 6.5 CM (Howa with a 24” barrel) - one with 140gr ELD-M and the other with 143 ELD-X. Both using once fired Hornady brass, Federal Match LR primers and H4350.

I loaded three rounds for each load starting at 37.5gr and working up in 0.5gr increments up to 41gr. So 24 rounds in total for the 140 ELD-M and 24 rounds for 143 ELD-X.

On Saturday I took half the day and slowly worked through the two sets shooting over the Crony and checking the groupings at 100y.

140 ELD-M
I am a bit disappointed. Found a couple of speed nodes and 6 out of 8 groups was sub moa (best being 0.18). Best average velocity was 2644 at 41gr.


143 ELD-X
Did better much than the ELD-M’s. Again found a couple of speed nodes with three groups giving an ES of 9,2 and 7 respectively. All sub moa with the best being 0.3. The last one (the one with an ES of 7, 0.7moa being at 41gr) also gave the best average velocity of 2622.


At no point did I feel a heavy bolt lift. The primers looks the same as the primers in the factory ammo and no cratering. At 40 and 41gr I just, just start to make out a very light ejector mark on some casings.

I really want to try and get to 2700fps, so my thinking is to work up another batch of loads starting at 41.2gr and increment 0.2gr increments up to 42gr (which is 0.5gr over Hornady book max).

Can I ask you guys with more experience doing load development, do you see anything in my uploaded photos that I am missing in terms of danger signs?

How about my strategy with the next step to work in 0.2gr up to 42gr?

Thanks for your feedback and advice!


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Nope, those primers look OK
Can’t see the ejector marks ?
Going up in 0.2 should be fine, TBH the book maxs have come down over the years, probably
due to the threat of litigation.

Originally Posted by Frogfeatures

Nope, those primers look OK
Can’t see the ejector marks ?
Going up in 0.2 should be fine, TBH the book maxs have come down over the years, probably
due to the threat of litigation.

Thanks, I was hoping that I was still on the right track.



Look at the “a” in the “Hornady” for the marking. Had to use a magnifying glass to see it.


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Originally Posted by Frogfeatures

Nope, those primers look OK
Can’t see the ejector marks ?
Going up in 0.2 should be fine, TBH the book maxs have come down over the years, probably
due to the threat of litigation.

I recon those primers still look fine too

Originally Posted by DLW

I recon those primers still look fine too

Thanks @DLW


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@janleroux I have a Howa 6.5CM 24inch heavy barrel

When running 140ELDM It really likes them at about 2770 FPS with a COAL of 2.840"

I find the standard 2.80 Factory COAL too much of a jump to the lands and builds up pressure faster with increasing charge weight.
In my Howa pressure signs start with an increasing ridge (primer cratering) around the primer strike well before I start getting ejector smear or sticky bolt lift.

H4350/2209 is certainly known for accuracy/temp insensitivity in 6.5cm

But don't discount RL16 also very temp stable and can give better MV and accuracy in my rifle

You might not be able to reach 2770 with a Coal of 2.80 before getting significant pressure signs.

Also you need to consider how many rounds have gone down your barrel if it's still new, less than 100 - 200 rounds, you may well find a speed increase as the barrel wears in.

Here's an example from QL for your bullet with H4350 in a 24" barrel note the COAL is 2.865 also note that the cartridge case capacity may not match yours if it's smaller pressures will reach higher.

Do not take any figures like these for gospel always start lower and work up.


Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 143, Hornady ELD-X 2635 G7
Useable Case Capaci: 46.313 grain H2O = 3.007 cm³
Cartridge O.A.L. L6: 2.865 inch = 72.77 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.704% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-07.0 94 39.32 2548 2061 48192 8838 97.3 1.347
-06.3 95 39.62 2566 2090 49240 8897 97.5 1.334
-05.6 96 39.92 2584 2120 50310 8956 97.7 1.321
-04.9 96 40.22 2602 2149 51405 9013 97.9 1.308 ! Near Maximum !
-04.2 97 40.51 2620 2179 52523 9069 98.1 1.296 ! Near Maximum !
-03.5 98 40.81 2638 2209 53665 9123 98.3 1.283 ! Near Maximum !
-02.8 98 41.11 2655 2239 54833 9176 98.5 1.271 ! Near Maximum !
-02.1 99 41.41 2673 2269 56026 9227 98.7 1.259 ! Near Maximum !
-01.4 100 41.70 2691 2299 57245 9277 98.8 1.246 ! Near Maximum !
-00.7 101 42.00 2709 2330 58492 9325 99.0 1.235 ! Near Maximum !
+00.0 101 42.30 2727 2361 59766 9372 99.1 1.223 !DANGEROUS LOAD-DO NOT USE!
+00.7 102 42.60 2744 2391 61069 9417 99.2 1.211 !DANGEROUS LOAD-DO NOT USE!
+01.4 103 42.90 2762 2422 62402 9460 99.3 1.200 !DANGEROUS LOAD-DO NOT USE!
+02.1 103 43.19 2780 2453 63764 9502 99.4 1.188 !DANGEROUS LOAD-DO NOT USE!
+02.8 104 43.49 2797 2484 65157 9543 99.5 1.177 !DANGEROUS LOAD-DO NOT USE!
+03.5 105 43.79 2815 2516 66582 9581 99.6 1.166 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 101 42.30 2832 2547 70203 9091 100.0 1.144 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 42.30 2580 2114 49511 9234 94.4 1.326

Originally Posted by spada

@janleroux I have a Howa 6.5CM 24inch heavy barrel

When running 140ELDM It really likes them at about 2770 FPS with a COAL of 2.840"

I find the standard 2.80 Factory COAL too much of a jump to the lands and builds up pressure faster with increasing charge weight.
In my Howa pressure signs start with an increasing ridge (primer cratering) around the primer strike well before I start getting ejector smear or sticky bolt lift.

H4350/2209 is certainly known for accuracy/temp insensitivity in 6.5cm

But don't discount RL16 also very temp stable and can give better MV and accuracy in my rifle

You might not be able to reach 2770 with a Coal of 2.80 before getting significant pressure signs.

Also you need to consider how many rounds have gone down your barrel if it's still new, less than 100 - 200 rounds, you may well find a speed increase as the barrel wears in.

Here's an example from QL for your bullet with H4350 in a 24" barrel note the COAL is 2.865 also note that the cartridge case capacity may not match yours if it's smaller pressures will reach higher.

Do not take any figures like these for gospel always start lower and work up.


Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 143, Hornady ELD-X 2635 G7
Useable Case Capaci: 46.313 grain H2O = 3.007 cm³
Cartridge O.A.L. L6: 2.865 inch = 72.77 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.704% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-07.0 94 39.32 2548 2061 48192 8838 97.3 1.347
-06.3 95 39.62 2566 2090 49240 8897 97.5 1.334
-05.6 96 39.92 2584 2120 50310 8956 97.7 1.321
-04.9 96 40.22 2602 2149 51405 9013 97.9 1.308 ! Near Maximum !
-04.2 97 40.51 2620 2179 52523 9069 98.1 1.296 ! Near Maximum !
-03.5 98 40.81 2638 2209 53665 9123 98.3 1.283 ! Near Maximum !
-02.8 98 41.11 2655 2239 54833 9176 98.5 1.271 ! Near Maximum !
-02.1 99 41.41 2673 2269 56026 9227 98.7 1.259 ! Near Maximum !
-01.4 100 41.70 2691 2299 57245 9277 98.8 1.246 ! Near Maximum !
-00.7 101 42.00 2709 2330 58492 9325 99.0 1.235 ! Near Maximum !
+00.0 101 42.30 2727 2361 59766 9372 99.1 1.223 !DANGEROUS LOAD-DO NOT USE!
+00.7 102 42.60 2744 2391 61069 9417 99.2 1.211 !DANGEROUS LOAD-DO NOT USE!
+01.4 103 42.90 2762 2422 62402 9460 99.3 1.200 !DANGEROUS LOAD-DO NOT USE!
+02.1 103 43.19 2780 2453 63764 9502 99.4 1.188 !DANGEROUS LOAD-DO NOT USE!
+02.8 104 43.49 2797 2484 65157 9543 99.5 1.177 !DANGEROUS LOAD-DO NOT USE!
+03.5 105 43.79 2815 2516 66582 9581 99.6 1.166 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 101 42.30 2832 2547 70203 9091 100.0 1.144 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 42.30 2580 2114 49511 9234 94.4 1.326

Wow, thanks! I will digest this a bit. Very good info and comparisons to have. Appreciate it!


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Originally Posted by spada

@janleroux I have a Howa 6.5CM 24inch heavy barrel

When running 140ELDM It really likes them at about 2770 FPS with a COAL of 2.840"

I find the standard 2.80 Factory COAL too much of a jump to the lands and builds up pressure faster with increasing charge weight.
In my Howa pressure signs start with an increasing ridge (primer cratering) around the primer strike well before I start getting ejector smear or sticky bolt lift.

H4350/2209 is certainly known for accuracy/temp insensitivity in 6.5cm

But don't discount RL16 also very temp stable and can give better MV and accuracy in my rifle

You might not be able to reach 2770 with a Coal of 2.80 before getting significant pressure signs.

Also you need to consider how many rounds have gone down your barrel if it's still new, less than 100 - 200 rounds, you may well find a speed increase as the barrel wears in.

Here's an example from QL for your bullet with H4350 in a 24" barrel note the COAL is 2.865 also note that the cartridge case capacity may not match yours if it's smaller pressures will reach higher.

Do not take any figures like these for gospel always start lower and work up.


Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 143, Hornady ELD-X 2635 G7
Useable Case Capaci: 46.313 grain H2O = 3.007 cm³
Cartridge O.A.L. L6: 2.865 inch = 72.77 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.704% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-07.0 94 39.32 2548 2061 48192 8838 97.3 1.347
-06.3 95 39.62 2566 2090 49240 8897 97.5 1.334
-05.6 96 39.92 2584 2120 50310 8956 97.7 1.321
-04.9 96 40.22 2602 2149 51405 9013 97.9 1.308 ! Near Maximum !
-04.2 97 40.51 2620 2179 52523 9069 98.1 1.296 ! Near Maximum !
-03.5 98 40.81 2638 2209 53665 9123 98.3 1.283 ! Near Maximum !
-02.8 98 41.11 2655 2239 54833 9176 98.5 1.271 ! Near Maximum !
-02.1 99 41.41 2673 2269 56026 9227 98.7 1.259 ! Near Maximum !
-01.4 100 41.70 2691 2299 57245 9277 98.8 1.246 ! Near Maximum !
-00.7 101 42.00 2709 2330 58492 9325 99.0 1.235 ! Near Maximum !
+00.0 101 42.30 2727 2361 59766 9372 99.1 1.223 !DANGEROUS LOAD-DO NOT USE!
+00.7 102 42.60 2744 2391 61069 9417 99.2 1.211 !DANGEROUS LOAD-DO NOT USE!
+01.4 103 42.90 2762 2422 62402 9460 99.3 1.200 !DANGEROUS LOAD-DO NOT USE!
+02.1 103 43.19 2780 2453 63764 9502 99.4 1.188 !DANGEROUS LOAD-DO NOT USE!
+02.8 104 43.49 2797 2484 65157 9543 99.5 1.177 !DANGEROUS LOAD-DO NOT USE!
+03.5 105 43.79 2815 2516 66582 9581 99.6 1.166 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 101 42.30 2832 2547 70203 9091 100.0 1.144 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 42.30 2580 2114 49511 9234 94.4 1.326

I am standing at about 150 rounds through this barrel. Very interesting to compare my results with QL output:

CHARGE AVE VEL (fps) ES GRP MOA
Factory 2669 43 0.77
37.5 2460 43 0.66
38.0 2462 61 0.37
38.5 2535 51 0.75
39.0 2527 11 0.65
39.5 2566 9 0.3
40.0 2598 2 0.57
40.5 2602 36 0.69
41.0 2622 7 0.71

My plan was to only go up to 42gr max - so this is inline with my next steps. Thanks!

I to would agree with others and say they look fine.

When you are getting hotter with your loads, I would suspect you will know and figure it out. Increase in recoil/ plus bolt lift and extraction will feel different.

What powder are you using in the 6.5creed?

Originally Posted by matagouri

I to would agree with others and say they look fine.

When you are getting hotter with your loads, I would suspect you will know and figure it out. Increase in recoil/ plus bolt lift and extraction will feel different.

What powder are you using in the 6.5creed?

Thanks. I am using Hodgdon H4350.


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Those cases show a mild load. Not even the slightest sign of excessive pressure. You've room for movement there. Go up in .3 grs and you should easily reach 2,700 fps safely.

Regarding SD. It's not that critical unless you're shooting at extreme range; accuracy is more important.

My Tikka 24" 6.5 CM has a long throat and magazine and to get 2,600 fps I have to load around 42.6 gr of H4320 from memory. I have settled on 44.3 grs for 2,750 fps with Lapua SP cases and 143 ELD-X. Note, that this load would be too hot in some rifles but is just warm in mine. I can easily get 2,800 fps with RE16 with about the same pressure as the H4320 at 2,750 fps.

BTW: H4320 is AR2209, exactly the same powder. ADI supply Hodgdon with AR2209 and they repack it under their name. I've used both at different times and had identical velocities. AR2209 is a little less expensive to buy and you also get 500gms vs 1lb for the Hodgdon.

Originally Posted by 10-Ring

Those cases show a mild load. Not even the slightest sign of excessive pressure. You've room for movement there. Go up in .3 grs and you should easily reach 2,700 fps safely.

Regarding SD. It's not that critical unless you're shooting at extreme range; accuracy is more important.

My Tikka 24" 6.5 CM has a long throat and magazine and to get 2,600 fps I have to load around 42.6 gr of H4320 from memory. I have settled on 44.3 grs for 2,750 fps with Lapua SP cases and 143 ELD-X. Note, that this load would be too hot in some rifles but is just warm in mine. I can easily get 2,800 fps with RE16 with about the same pressure as the H4320 at 2,750 fps.

BTW: H4320 is AR2209, exactly the same powder. ADI supply Hodgdon with AR2209 and they repack it under their name. I've used both at different times and had identical velocities. AR2209 is a little less expensive to buy and you also get 500gms vs 1lb for the Hodgdon.

Thanks @10-Ring. I want to get more into long range shooting as well, so I looking for as consistent velocity but with accuracy. This is why I am not trying to get the highest possible velocity out of it, just a constant 2700’ish.

Thanks for the info about RE16. I have decided to start with H4350 because I am doing my load development in winter and it is supposed to be quite temp insensitive. Also another reason why I not keen to run on maximums at this stage.


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Originally Posted by 10-Ring

Those cases show a mild load. Not even the slightest sign of excessive pressure. You've room for movement there. Go up in .3 grs and you should easily reach 2,700 fps safely.

Regarding SD. It's not that critical unless you're shooting at extreme range; accuracy is more important.

My Tikka 24" 6.5 CM has a long throat and magazine and to get 2,600 fps I have to load around 42.6 gr of H4320 from memory. I have settled on 44.3 grs for 2,750 fps with Lapua SP cases and 143 ELD-X. Note, that this load would be too hot in some rifles but is just warm in mine. I can easily get 2,800 fps with RE16 with about the same pressure as the H4320 at 2,750 fps.

BTW: H4320 is AR2209, exactly the same powder. ADI supply Hodgdon with AR2209 and they repack it under their name. I've used both at different times and had identical velocities. AR2209 is a little less expensive to buy and you also get 500gms vs 1lb for the Hodgdon.

Do you mean H4350? According to ADI website this is the equivalent of AR2209. It appears H4320 doesn’t exist, though there is IMR4320, which ADI reckon is close to AR2208.

Originally Posted by Cigar

Do you mean H4350? According to ADI website this is the equivalent of AR2209. It appears H4320 doesn’t exist, though there is IMR4320, which ADI reckon is close to AR2208.

He said Hodgdon 4350 at first. Not a powder I'd expect to hear mentioned in connection with overpressure, unless you only half filled the case and had some detonation kind of thing going on. Some recommend magnum primers for slow powders, but go by the book. H4350 "likes" heavier projectiles btw.

Originally Posted by Cordite

He said Hodgdon 4350 at first. Not a powder I'd expect to hear mentioned in connection with overpressure, unless you only half filled the case and had some detonation kind of thing going on. Some recommend magnum primers for slow powders, but go by the book. H4350 "likes" heavier projectiles btw.

Hi @Cordite, that is interesting comment you made that I did not know - so are you saying that you could run into over pressure if you under load as well? Is it because there is not sufficient pressure to move the projectile out of the barrel and you have pressure peaking somewhere during the process?


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