Interesting Quickload experience with RL25 and RL26 for 6.5x284 Norma

[DLrocket89]

I picked up a Savage 111 Trophy Hunter XP in 6.5x284 Norma a few months back. Most of the reloading data I'd seen online recommended H4831SC or H4350. I picked up a pound of H4831SC as the baseline and then went in search of other things I had laying around.

The powders I had were H4831SC as mentioned, RL17, RL19, RL25, and RL26 (what can I say, Allliant is readily available where I am...). All shooting a 143 Grain ELD-X, CCI No 200 primers, Lapua brass, and a COAL of .025" off of the lands (3.156")

The predicted MVs for the H4831SC were accurate to within single digit fps differences across all the charge weights I tried. The Reloder powders, all of them, started out matching the QL predicted pretty well (+/- 15 fps) but then as I got up to max pressure the velocities sky rocketed and deviated from predicted by sometimes 50fps, and with a pretty sudden onset of pressure signs.

Couple of questions...
1) anyone else ever seen this happen with Reloder powders? Sudden spike in MV? Or is the QL model just breaking down...?
2) max accuracy with RL19, RL25, and RL26 all happened just prior to the MV shooting up. On all of the Reloders. anyone see anything similar?

Some data points:
H4831SC - 51.0 gn - 2735 fps, 42 SD
RL17 - 45.5 gn - 2690 fps, 22 SD (pressure signs at 47.0 gns)
RL19 - 50.0 gn - 2801 fps, 10 SD
RL25 - 53.0 gn - 2817 fps, 7 SD
RL26 - 51.5 gn - 2903 fps, 8 SD (pressure signs at 53.0 gns)

Using the RL25 loading above, I was hitting a 4" gong at 350 yards about 80-90% of the time off of a shooting table and bipod. Not bad for a $500 gun!!!

 

[Bart B.]

as I got up to max pressure the velocities sky rocketed and deviated from predicted by sometimes 50fps, and with a pretty sudden onset of pressure signs.

That happens often.

As your barrel, component lots and ammo details are different than Quickloads stuff used to edtimate what others might get, no way will your loads behave the same as theirs.

 

[rsrocket1]

I find that Quickload works very well for middle of the road loads and is a great tool for "what if" situations using all sorts of different powders.

I don't believe the results under certain circumstances.

- Terribly unsuitable powders such as "rifle speed" powders in pistol cartridges or magnum speed pistol powders used short/wide pistol cases. It does often work the other way. I find it fairly accurate when predicting speeds in fast powders used in rifle cartridges such as Red Dot, Unique, RL7 in .308 cartridges at speeds below 2000 fps.

- Really short (snubnose) barrel velocity predictions

- "wonky" looking burn curves such as "kinks" in what should be a smooth curve

- Predictions near or over max loads. With pistol loads, it often looks a little too pessimistic meaning the pressures look much higher than even published loads show.

I don't use it when the pressure/velocity curve is high in the violet zone or when the predicted powder consumption is below 75% before the bullet exits the barrel.

 

[DLrocket89]

Thanks for the thoughts Bart and Rocket. This all makes sense. I certainly don't use QL as absolute truth, just using it for comparative things, seems to work well within the bonds mentioned above.

Rocket - I was throwing out powders that were <90% burned as one of my criteria, glad to hear someone else is using that as criteria.