6.5 creedmoor QL hulp asb.

[Dale SH]

With 0.5 weighting factor

[Dale SH]

With 0.6 weighting factor
I chose to use the 0.6 weighting factor

[Dale SH]

I edited my original prediction to 42.2 grains as I realised I made a typing error.
This is almost the exact same load for a friend who uses the Howa 24 inch bull barrel with S365 and 140 grain Nosler CC

[Dale SH]

Lets see a screenshot of your prediction with the 140 grain Nosler CC

[JohanvB]

Lets see a screenshot of your prediction with the 140 grain Nosler CC

If I have all the values I would gladly do so.

Your two screen shots, on which one of the loads that JJ777 used, did you calibrate QL?

[Dale SH]

Lets see a screenshot of your prediction with the 140 grain Nosler CC

If I have all the values I would gladly do so.

Your two screen shots, on which one of the loads that JJ777 used, did you calibrate QL?

Yes of course.
There is no other way to use the software correctly.
I always use the highest load (41.8 grains) as this gives the truest reflection of the BRF at the "highest" pressure.

[JohanvB]

JJ777 first load of 40.5 at 2536 fps.

40.5.png

[Gbyleveldt]

Dale,

As a matter of interest, this was my QL prediction for the 140gn Nosler CC's in a Howa 24" Bull Barrel. I'm not running S365 but IMR4350. I ended up settling for 41.8gn IMR4350 as that's the charge that showed the nicest groups and almost in the middle of a nice fat node. Speed ended up at 2717fps.

I'm curious as to your weighing factor of 0.6? Genuinely interested.

[Dale SH]

If someone requests a QL prediction but their pressure is below 45000 psi or 50 000 psi in an overbore cartridge then I would make a recommendation that they shoot again with a higher but safe charge, to ascertain where there BRF actually is once they have crossed the 50 000 psi mark.
Unless they deliberately want to achieve a "slower" node.

[JohanvB]

His load of 40.5 calibrated showing that he must load 45.06 for a speed of 2846

40.5 calibrated.png

[JohanvB]

If I have done something wrong pse advise, we are here to learn.

[Dale SH]

JJ777 first load of 40.5 at 2536 fps.

40.5.png

The pressure generated here is too low to make an accurate prediction as to where his BRF will increase with the higher pressure.

[JohanvB]

41.8

41.8.png

41 .8 calibrated

41.8 calibrated.png

[Dale SH]

His load of 40.5 calibrated showing that he must load 45.06 for a speed of 2846

40.5 calibrated.png

I also note that you are using the "new" thermochemical properties for S365
Driepoort, Gawie and Myself use the "previous" values.
With the "new" values the BRF is abnormally low and shows that one has to load substantially more propellant to achieve a node.
This is a dangerous practice.
Tried this myself with a 308 and hat hit the bolt open with a wooden hammer.
Primer had blown out of the pocket.

[JohanvB]

Ok, thank you.

I take note of your comment.

So far this has worked for me, but say again I will take note your comment.

This is how we learn

[Dale SH]

Use the highest possible safe load that the OP shot to calibrate the BRF and use the "old" thermochemical values.
This way you will end up with the most accurate possible BRF and most accurate prediction.

As mentioned before unless the user deliverately wants to achieve a "slower" Node

[Dale SH]

Additionally is you use the old values and you end with an unreasonably high BRF then this is an indication that something is out of kilter with the ballistics and you can start asking question like:
Is the an overbore cartridge and is it throttling pressure above the 50 000 psi mark
Is the bullet seated into the rifling.
etc etc

It is a good diagnostic tool if you use it this way.

[JohanvB]

Hi Dale

Ok..this is bothering me ..so, my lower node at 1.308 sits at 2727 fps..do you agree with this?

41.8 node .308.png

[Gbyleveldt]

My higher node at 1.228 sits at 2735fps. This is bothering me as well...

Edit: this with 140gn Nosler CC which are 3mm shorter if memory serves.

[Dale SH]

Morning Gents.

I will answer you a little later as I am on my way to work.
There is a lot of debate around what the correct Saami Max pressure is for the 6.5 Creedmoor.
In short I believe that the max pressure is correct at 60 000 psi but the cases with large rifle pocket primers can not handle these pressures and thus the whole debarcle about the original Hornady/Norma cases blowing primers and stretching primer pockets with loads at around 58000 psi.
Alll the bullet and propellant manufacturers subsequently reduced their max loads on the reloading data tables to overcome this problem.
https://www.vihtavuori.com/reloading-da ... rtridge=95
https://load-data.nosler.com/load-data/65-creedmoor/
http://www.somchemreload.com/search?c=8&f=353
If I reverse calculate these loads in QL they all equate to +- 55000 to 56000 psi which is where you would expect the bullet and propellant manufacturers to set their max presssures at, considering a small built in safety margin.
The original load data and factory ammo from Hornady was calculated at 58000 psi before the primer issues arose.
When Lapua introduced the small primer pocket cases, this seemed to overcome the problem and a small primer pocket case has a much stronger head/web area.

I have attached this piece from another forum.
Please read it.
When the 6.5mm Creedmoor was first introduced it was advertised as a 60,000 psi capable case.[6] However, when it was placed into production Hornady listed it as 62,000 psi and had it SAAMI registered as such. For this reason many hand loaders have had poor experiences reloading for it. Blown primers on the first shot at 62,000 psi are not uncommon. Early shooting articles listed the ammo as loaded to 58,000 psi[20] but later ones list it as 57,000 psi.[21] This is because Hornady reduced the loads in its factory ammo because of complaints that it was often blowing primers.[22] Lapua delivered 6.5mm Creedmoor brass at Shot show 2017,[23] and production quantities became available via major retailers in second quarter 2017. The Lapua version has a small primer pocket.[16][24] Thus, loads from a Lapua Creedmoor are not safe in another manufacturer's Creedmoor brass that features a large primer pocket without applying proper hand loading test for pressure first. Also the use of a smaller diameter decapping rod is required to size and decap.

[Dale SH]

Hi Dale

Ok..this is bothering me ..so, my lower node at 1.308 sits at 2727 fps..do you agree with this?

41.8 node .308.png

Johan.

Contrary to my advise yesterday, I see you have once again used the "new" thermochemical factors for S365, which includes a propellant density of 1.55g/ cubic cm which in itself makes a big difference to presssure generated.
So my answer in short is no I can not agree with your calculation.
Once again the "new" values show an unreasonably low BRF factor relative to the QL default of 0.44 and this in itself should tell you something.

Attached find JJ777's calibration load done the way we do it.

[Dale SH]

Further to my statement this morning regarding the Lapua small primer pocket cases, then put in simplistic terms.
For the 6.5 Creemoor shooters, If you want to chase Node 5 at +- 2790 to 2800 fps ( 59 to 60k psi) from a 24 inch barrel, then make sure you using Lapua small primer pocket brass, or you have a 26 inch barrel (2800 fps @ +- 55400 psi)
Do not attempt this with large primer pocket brass, it will blow the primers out the pocket or at least stretch the primer pockets so badly that you wont get more than 2 to 3 firings from a case before you have to throw it away.

[Wouter Roets]

Further to my statement this morning regarding the Lapua small primer pocket cases, then put in simplistic terms.
For the 6.5 Creemoor shooters, If you want to chase Node 5 at +- 2790 to 2800 fps ( 59 to 60k psi) from a 24 inch barrel, then make sure you using Lapua small primer pocket brass, or you have a 26 inch barrel (2800 fps @ +- 55400 psi)
Do not attempt this with large primer pocket brass, it will blow the primers out the pocket or at least stretch the primer pockets so badly that you wont get more than 2 to 3 firings from a case before you have to throw it away.

Hallo Dale

Ek glo jy het gelees wat ek al n hele rukkie terug geskryf het oor die 6.5 Creedmoor en QL. Ek sal bietjie gaan soek en die link hier plaas indien jy dit nie raakgelees het nie. Wat jy hier se weerspieel basies my ondervinding en redenasie rondom die kwessie. Ek kan maar net weer dit onder almal se aandag bring dat die maksimum spoed met n 140gr koeel uit n 24 duim loop met geen poeie, plaaslik of internationaal veel hoer is as 2700ft/sek nie. Maak nie saak wat se dop gebruik word nie, deur hoer snelhede as dit te hardloop oorskrei jy maksimum drukvlakke vir die kaliber gepaardgaande met al die gevare daaraan verbonde. Mense ek kan nie hierdie genoeg stres nie en ek smeek dat julle dit sal inneem en toepas vir julle en die mense om julle se veiligheid.

Groetnis
Wouter

[Dale SH]

Hello Wouter.

Yes I did read your writings about the caliber.

Would you please in your opinion clarify a few things for me:
Do you believe that the Creedmoor is not capable of 2800 fps with a 24 inch barrel because:

1. To achieve the above, the loads are genuinely over SAAMI MAX pressure or
2. The original large primer pocket cases where never designed to handle the pressure at 58 to 60 psi presssure.
3. The stated SAAMI max presssure is optimistic and should never have been set that high considering that the parent case for the 6.5 Creedmoor is the 30BR which has a SAAMI max pressure of 58700 psi and the original large primer pocket case was never "strengthened" to accomodate the higher pressures ?

Im keen to hear your thoughts.

[Gawie(13mm)]

Ek luister ook by die radio.
Nes Dale, glo ek ook dat gesonde verstand moet seëvier en dat een man se bakgat lading, 'n ander man se pypbom is.