Has Quick loads data calibration improved for the 6.5 Grendel yet?

[SDguy]

I have been pondering my experience last season with Leverevolution and 129 grain core locks & 125 grain partitions in a bolt action CSS chambered bolt action CZ527 last fall.

I am wondering if any better information may be available regarding pressure expectations with non listed propellants. CFE 223 and LVR are the propellants I am most interested in.

Velocities I was getting with the 125 and 129 grain cup and core bullets measured with three diffrent chronographs seems un-real to me as I was well into Creedmoor velocities before showing pressure signs to cause me to back off with Leverevolution. Not far short of creedmoor velocities before accuracy started to deteriorate.

While I feel very safe with my preferred hunting load ( 2 grains less than max load I have tried), based on pressure signs I still would like more data to back up my experience thus far.

Anyone tried a recent version of quick loads with Leverevolution & 129 grain class bullet in the 6.5 Grendel?

[JASmith]

I have also been taken aback by the poor correlation of QuickLoad in both velocity and pressure.

The good news is that the slopes of both the velocity and pressure curves match those I get with the Marnetospeed and the RSI equipment.

One of the ballisticians at Western Powders told be that the root cause for the poor calibration is most probably the proximity of the bullet base to the primer. The primer gives a rather significant kick up close. This causes the bullet to start moving sooner than is the case with the more classic cartridges the program was built for. That means there is no allowance in the software for this phenomena.

The math model would need to be updated and a small rewrite undertaken to bring more in line with folks' experiences in other cartridges.

My best advice is to send notes to the author requesting an update.

In the meantime, one can calibrate the velocity curves for each bullet and powder combo one plays with,

PM me for more calibration discussions.

[IceAxe]

I too get better results after "calibrating" the Quickload data.

[CCW]

I have found that the german is not want to fiddle with the code or input data to suit users, including changing bullet weights in the catalog to match actual bullet weights.

Also have found that case volume via. fired case-max-fill to top of neck in H2O grains is one parameter often overlooked that can settle down predicted vs. actual speed variations.

Hornady has carefully tuned its ammo including using 123 SST weight to assure magazine feed and minimize "shank-in-case" variations. The HDY ballistician warned me that using their older 129 SST could lead you off into "your mileage may vary", particularly for gas guns using the cannelure crimp.

I was happy to report that their published dope on the #8152 box agreed exactly with my measured MV at 10 ft. (24" Satern 5R SST, no brake).

[barrelcactus]

Quickload does a really good job on the 120 to 125gr bullets with the Satern 5R barrels but drifts off a bit in its predictions for the 100gr and below and the 129gr and above.

[JASmith]

Quickload does a really good job on the 120 to 125gr bullets with the Satern 5R barrels but drifts off a bit in its predictions for the 100gr and below and the 129gr and above.

Not an accurate statement.

Quickload does well in both pressure and velocity space for only about 1/3 of the bullets and powders I have tested. Velocity 'seems' to correlate better than pressure but I suspect that is because velocity is proportional to the square root of energy. The variations result in pressures significantly higher and sometimes disturbingly lower than the QL predictions.

To cherry-pick and example, the 123gr AMAX QL pressure is 15000 psi higher than what I see with Pressure Trace / RSI. The velocity seems closer, beight 'just' 125 fps lower than the test results indicate.

That means that one cannot use QuickLoad to reliably predict whether a load might be safe. Further, the velocity data will be unreliable too.

Even though the first part of this post seems like a condemnation of QuiickLoad, it is not. I find QuickLoad very useful during load work up because both the pressure and velocity curve slopes track niceley with experiment. That means that a predicted 50 fps change in velocity results in the same increment within experimental error. The same is true for pressure

I am using an Encore with a Bullberry barrel and calibrated the gage to a double handful of loads where pressure and velocity were reported by powder companies.

[barrelcactus]

Not an accurate statement.

Quickload does well in both pressure and velocity space for only about 1/3 of the bullets and powders I have tested. Velocity 'seems' to correlate better than pressure but I suspect that is because velocity is proportional to the square root of energy. The variations result in pressures significantly higher and sometimes disturbingly lower than the QL predictions.

To cherry-pick and example, the 123gr AMAX QL pressure is 15000 psi higher than what I see with Pressure Trace / RSI. The velocity seems closer, beight 'just' 125 fps lower than the test results indicate.

That means that one cannot use QuickLoad to reliably predict whether a load might be safe. Further, the velocity data will be unreliable too.

Even though the first part of this post seems like a condemnation of QuiickLoad, it is not. I find QuickLoad very useful during load work up because both the pressure and velocity curve slopes track niceley with experiment. That means that a predicted 50 fps change in velocity results in the same increment within experimental error. The same is true for pressure

I am using an Encore with a Bullberry barrel and calibrated the gage to a double handful of loads where pressure and velocity were reported by powder companies.

I find velocity way off for the 140gr and the 85gr bullets while it right on the money for the 123gr bullets.

[barrelcactus]

It also does not predict barnes very well.

[SDguy]

JASmith

If you or any one else here has any pertinent data or experiences with Leverevolution in the 6.5 Grendel I would be grateful if you would share your findings.

a posting here would be fine and if you are more comfortable with a PM that would be fine as well.

Thank you all!