Quickload simulation help

[5.0rick]

Hi Guys,

I am starting from scratch on a new load for my BHW 18" and was hoping someone with Quickload would be nice enough to run a few simulations for me to help me find the OBT. Here is what I will be using.

Hornady Brass
CCI450 primer
CFE 223 Powder
Lapua Scenar-L 120 grain HPBT

I am starting with 31 grains of powder and have been told not to exceed 32 grains. I am hoping that the sweet spot is somewhere in that range. I believe the OBT for an 18" barrel is .989 for node 6, still not clear on which node to use.

Any help is much appreciated.

Rick

[rwh]

Quickload asks for the length of your case, the length of the cartridge (base to tip) and the volume of the case measured in grains of H2O and even with all that it's not that great at predicting for the grendel. You would be much better off and a lot safer if you just start low and work up. That said here's what I get using the values from my lapua brass. I would put zero faith in the pressure number in particular.

6.5 Grendel (SAAMI), 18" barrel

Cartridge length: 2.260
Case length: 1.520
Case volume: 38 grains H2O
Propellant: CFE223
Charge Weight: 31.0 grains
Max Pressure: 50509 psi
Muzzle Velocity: 2487 fps

[NugginFutz]

No experience with quick load, but I've loaded similar combinations in a BHW 18". Start 10% low from max weight and come up in 1% (.3 grain) increments. I've seen as many as three accuracy nodes in that span with my BHW barrels. It'd be a shame to start too high and potentially miss a nice wide node. Starting 10% down will also allow you to monitor for pressure signs starting from a known safe level.

[5.0rick]

Quickload asks for the length of your case, the length of the cartridge (base to tip) and the volume of the case measured in grains of H2O and even with all that it's not that great at predicting for the grendel. You would be much better off and a lot safer if you just start low and work up. That said here's what I get using the values from my lapua brass. I would put zero faith in the pressure number in particular.

6.5 Grendel (SAAMI), 18" barrel

Cartridge length: 2.260
Case length: 1.520
Case volume: 38 grains H2O
Propellant: CFE223
Charge Weight: 31.0 grains
Max Pressure: 50509 psi
Muzzle Velocity: 2487 fps

Thanks for the info. What did you get for OBT (optimal barrel time)?

Rick

[5.0rick]

Went to the range today and tested some loads at 100 yards. Looks like 31.2 grains was close. Going to try 31.1 and 31.3 grains next.

O-give was set to 1.727
Hornady brass
CCI450 primer
CFE 223 from 31 grains to 32 grains in .2 increments.

[5.0rick]

RWH, I measured the case volume on my Hornady brass and it came in at 34.6 grains of H2O. The case length is 1.518. Would you mind running a simulation in quick load for me? The powder change is 31.2 grains and the COAL is 2.255 or 1.727 base to O-give. I am particularly interested on what the OBT is (Optimum Barrel Time).

Thanks,

Rick

[rwh]

Did you get the volume from a fired case? It sounds low unless the hornady cases use really thick brass.

[5.0rick]

RWH, yes it is the volume of a fired case. I will say, it seems much thicker than my converted 7.62x39 brass. I have not measured that yet.

[rwh]

I guess I will be sticking to Lapua brass from now on. Grendel needs all the boiler room it can get.

6.5 Grendel (SAAMI), 18" barrel

Cartridge length: 2.260
Case length: 1.518
Case volume: 34.6 grains H2O
Propellant: CFE223
Charge Weight: 31.2 grains
Max Pressure: 68637 psi <<< WAY TOO HOT
Muzzle Velocity: 2655 fps
Barrel Time: .897 ms

[5.0rick]

Thank you RWH. I plan on testing 31.1 and 31.3 tomorrow. Just out of curiosity, would you run those charges to see what the barrel time is? According to what I have found the nodes are .619,.681,.771,.835,.924,.989, 1.077. Just wondering if either .1 or .3 gets me closer.

Thanks again.

Rick

[Cornbread]

I would not call that a good combination. If .2 grains opens the groups up that much on either side then the node is to narrow. Cfe is known to be temp sensative. It wouldnt take much to throw your velocity out of that node.

[LRRPF52]

I guess I will be sticking to Lapua brass from now on. Grendel needs all the boiler room it can get.

6.5 Grendel (SAAMI), 18" barrel

Cartridge length: 2.260
Case length: 1.518
Case volume: 34.6 grains H2O
Propellant: CFE223
Charge Weight: 31.2 grains
Max Pressure: 68637 psi <<< WAY TOO HOT
Muzzle Velocity: 2655 fps
Barrel Time: .897 ms

Quick Load is so far off with that prediction, it isn't even funny. RSI Pressure Trace system and Hornady's data show much slower speeds and pressure than that with a SAAMI chamber. QL is off by over 20,000psi in this case.

With 123gr AMAX:

31.1gr 2489fps 45,711psi
31.3gr 2520fps 47,302psi

QL is extremely unreliable for predictive peak pressure with this cartridge, and requires tuning. Hornady's 9th Edition shows 31.7gr max with 129gr cup and core bullets with CFE223.

Keep in mind that you always need to work up a load, with .3gr increments for 6.5 Grendel (1% case volume), that different powder lots can produce different pressures, your chamber and bore will build pressure differently, and standard reloading guidelines for safe load development.

[5.0rick]

Quick Load is so far off with that prediction, it isn't even funny. RSI Pressure Trace system and Hornady's data show much slower speeds and pressure than that with a SAAMI chamber. QL is off by over 20,000psi in this case.

With 123gr AMAX:

31.1gr 2489fps 45,711psi
31.3gr 2520fps 47,302psi

QL is extremely unreliable for predictive peak pressure with this cartridge, and requires tuning. Hornady's 9th Edition shows 31.7gr max with 129gr cup and core bullets with CFE223.

Keep in mind that you always need to work up a load, with .3gr increments for 6.5 Grendel (1% case volume), that different powder lots can produce different pressures, your chamber and bore will build pressure differently, and standard reloading guidelines for safe load development.

Thanks LRRPF52. Would you mind posting the barrel times for those charges?

Rick

[Klem]

The range of difference in QL output is in the case volume.

QL's default case capacity is 38gns of water, which in your CFE223/31.2gn scenario produces only 51,500lbs of peak pressure.

My Lapua fired cases are 36.4gns of water, which in this scenario produces 58.450lbs of peak pressure.

Sounds like Hornady cases have even less capacity.

QL is conservative so whenever I see it right on the edge of SAAMI I know I can push it a little more (plus noting all other signs of pressure).

[LRRPF52]

I personally don't see a difference between case capacity when I measured several samples of Lapua, Hornady, and even PPU brass.

Everything was around 35gr H2O.

No way that 31.2gr load is doing even 50ksi. Quick Load needs to be calibrated to get usable info for 6.5 Grendel. We've often seen 10ksi more predictions from it that were simply out to lunch.