QL Request 140's at different OCL

[andrewctillman]

I posted this a few days ago on the QL thread but have not heard back so appologies for also posting here.

I am loading the 140 ELD. 140 RDF and 147 ELD at both 2.890 and 2.915 OCL in my 6.5 Creedmoor. Rifle is a Tikka T3xCTR with very long throat. I would like some QL guidance to determine upper velocity threshold for RL-16.

If you all dont have time to calculate each bullet at both OCL, even one would be very helpful.

So far, I have found the two 140's are 75-108 fps slower at 2.890 OCL and the 147 is +12 fps faster.

6.5 Creedmoor.

140 Hornady ELD-M, 140 Nosler RDF, 147 Hornady ELD-M.

RL-16

2.890 OCL and 2.915 OCL all bullets. Hornady brass.

Bullet lengths are: 140 ELD, 1.374. 140 RDF, 1.420, 147 ELD-M, 1.440.

The Tikka T3x CTR appears to have a much longer than normal free bore (.199 standard) and jump to jam rifling is 2.950 for 140 ELD, 2,991 (140 RDF), and 3.009 (147 ELD).

Your help is much appreciated!

 

[Songdog]

The .025” delta in COAL will make absolutely no practical difference in velocity. QL May show 10fps difference.

I’ve loaded for a lot of CTRs, in both .260 and 6.5 Creed..... trust me when I say this.... you’re skull humping this thing to death. The Tikka throat and lead angle is magic, they shoot everything well. Start at just under Mag length.... and rock on. If you don’t find a good load there, pick your best one and start working backwards.

You did’t say if you have the 20” or 24” version... that will make a huge difference.

My 20” .260 CTR will hit 2800 with 139/140 grain bullets.

 

[andrewctillman]

Songdog,

I am shooting a 24 inch 6.5 CM.

And there was a large difference in velocity between the two seating depths.

I loaded up another batch to try and see if the results are repeatable.

PS Have you had any trouble with your CTR magazines? I get a high percentage of bolt over base with all 4 of mine.

 

[Dwh7271]

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 140, Nosler RDF HPBT 26725
Useable Case Capaci: 47.440 grain H2O = 3.080 cm³
Cartridge O.A.L. L6: 2.890 inch = 73.41 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   93    39.59   2681    2234   48535   9521     99.9    1.308
-06.3   94    39.89   2699    2264   49612   9561     99.9    1.295
-05.6   94    40.19   2717    2295   50711   9600    100.0    1.282
-04.9   95    40.49   2735    2326   51833   9635    100.0    1.270
-04.2   96    40.79   2753    2357   52984   9669    100.0    1.257
-03.5   96    41.09   2772    2388   54159   9701    100.0    1.245  ! Near Maximum !
-02.8   97    41.39   2790    2419   55362   9732    100.0    1.233  ! Near Maximum !
-02.1   98    41.69   2807    2450   56592   9763    100.0    1.221  ! Near Maximum !
-01.4   99    41.99   2825    2481   57850   9793    100.0    1.209  ! Near Maximum !
-00.7   99    42.29   2843    2513   59137   9824    100.0    1.198  ! Near Maximum !
+00.0  100    42.59   2861    2544   60455   9854    100.0    1.186  ! Near Maximum !
+00.7  101    42.89   2878    2576   61801   9883    100.0    1.175  ! Near Maximum !
+01.4  101    43.19   2896    2607   63180   9913    100.0    1.163  !DANGEROUS LOAD-DO NOT USE!
+02.1  102    43.49   2913    2639   64591   9942    100.0    1.152  !DANGEROUS LOAD-DO NOT USE!
+02.8  103    43.79   2931    2670   66036   9970    100.0    1.142  !DANGEROUS LOAD-DO NOT USE!
+03.5  104    44.09   2948    2702   67515   9999    100.0    1.131  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba    100    42.59   2894    2603   64006   9721    100.0    1.160  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba    100    42.59   2823    2478   57023  10004    100.0    1.215  ! Near Maximum !

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 140, Nosler RDF HPBT 26725
Useable Case Capaci: 47.786 grain H2O = 3.103 cm³
Cartridge O.A.L. L6: 2.915 inch = 74.04 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   92    39.59   2672    2220   47894   9549     99.9    1.316
-06.3   93    39.89   2690    2250   48949   9591     99.9    1.303
-05.6   94    40.19   2709    2281   50028   9630    100.0    1.290
-04.9   94    40.49   2727    2311   51128   9667    100.0    1.278
-04.2   95    40.79   2745    2342   52255   9702    100.0    1.265
-03.5   96    41.09   2763    2373   53387   9735    100.0    1.253
-02.8   96    41.39   2781    2404   54584   9766    100.0    1.241  ! Near Maximum !
-02.1   97    41.69   2799    2435   55790   9798    100.0    1.229  ! Near Maximum !
-01.4   98    41.99   2816    2466   57021   9829    100.0    1.217  ! Near Maximum !
-00.7   99    42.29   2834    2497   58280   9860    100.0    1.205  ! Near Maximum !
+00.0   99    42.59   2852    2528   59569   9890    100.0    1.193  ! Near Maximum !
+00.7  100    42.89   2869    2559   60886   9920    100.0    1.182  ! Near Maximum !
+01.4  101    43.19   2887    2591   62234   9950    100.0    1.171  ! Near Maximum !
+02.1  101    43.49   2904    2622   63615   9979    100.0    1.160  !DANGEROUS LOAD-DO NOT USE!
+02.8  102    43.79   2922    2654   65027  10009    100.0    1.149  !DANGEROUS LOAD-DO NOT USE!
+03.5  103    44.09   2939    2685   66471  10037    100.0    1.138  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     99    42.59   2885    2587   63067   9757    100.0    1.167  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba     99    42.59   2814    2461   56194  10040    100.0    1.222  ! Near Maximum !

 

[Dwh7271]

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 140, Hornady ELD-M 26331
Useable Case Capaci: 48.289 grain H2O = 3.135 cm³
Cartridge O.A.L. L6: 2.890 inch = 73.41 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   91    39.59   2660    2200   46996   9579     99.8    1.328
-06.3   92    39.89   2679    2230   48020   9622     99.9    1.315
-05.6   93    40.19   2697    2261   49067   9663     99.9    1.302
-04.9   93    40.49   2715    2291   50139   9702    100.0    1.289
-04.2   94    40.79   2733    2322   51229   9738    100.0    1.277
-03.5   95    41.09   2751    2352   52353   9773    100.0    1.264
-02.8   95    41.39   2769    2383   53495   9805    100.0    1.252
-02.1   96    41.69   2786    2413   54665   9837    100.0    1.240  ! Near Maximum !
-01.4   97    41.99   2804    2444   55860   9869    100.0    1.228  ! Near Maximum !
-00.7   98    42.29   2822    2475   57080   9900    100.0    1.216  ! Near Maximum !
+00.0   98    42.59   2839    2506   58330   9931    100.0    1.205  ! Near Maximum !
+00.7   99    42.89   2857    2537   59609   9962    100.0    1.193  ! Near Maximum !
+01.4  100    43.19   2874    2568   60915   9992    100.0    1.182  ! Near Maximum !
+02.1  100    43.49   2891    2599   62250  10023    100.0    1.171  ! Near Maximum !
+02.8  101    43.79   2909    2630   63616  10052    100.0    1.160  !DANGEROUS LOAD-DO NOT USE!
+03.5  102    44.09   2926    2662   65016  10082    100.0    1.149  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     98    42.59   2872    2565   61750   9797    100.0    1.178  ! Near Maximum !
Data for burning rate decreased by 3% relative to nominal value:
-Ba     98    42.59   2801    2439   55025  10080    100.0    1.234  ! Near Maximum !

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 140, Hornady ELD-M 26331
Useable Case Capaci: 48.633 grain H2O = 3.158 cm³
Cartridge O.A.L. L6: 2.915 inch = 74.04 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   91    39.59   2652    2187   46402   9605     99.8    1.335
-06.3   91    39.89   2670    2217   47407   9650     99.9    1.322
-05.6   92    40.19   2688    2247   48436   9692     99.9    1.309
-04.9   93    40.49   2706    2277   49487   9732    100.0    1.296
-04.2   93    40.79   2724    2307   50560   9769    100.0    1.284
-03.5   94    41.09   2742    2337   51658   9805    100.0    1.272
-02.8   95    41.39   2760    2368   52777   9838    100.0    1.259
-02.1   95    41.69   2778    2398   53923   9871    100.0    1.247  ! Near Maximum !
-01.4   96    41.99   2795    2429   55095   9903    100.0    1.235  ! Near Maximum !
-00.7   97    42.29   2813    2460   56291   9935    100.0    1.224  ! Near Maximum !
+00.0   98    42.59   2830    2490   57515   9966    100.0    1.212  ! Near Maximum !
+00.7   98    42.89   2848    2521   58767   9997    100.0    1.201  ! Near Maximum !
+01.4   99    43.19   2865    2552   60046  10028    100.0    1.189  ! Near Maximum !
+02.1  100    43.49   2882    2583   61352  10059    100.0    1.178  ! Near Maximum !
+02.8  100    43.79   2900    2614   62692  10089    100.0    1.167  !DANGEROUS LOAD-DO NOT USE!
+03.5  101    44.09   2917    2645   64059  10119    100.0    1.156  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     98    42.59   2864    2550   60881   9832    100.0    1.185  ! Near Maximum !
Data for burning rate decreased by 3% relative to nominal value:
-Ba     98    42.59   2792    2423   54265  10114    100.0    1.242  ! Near Maximum !

 

[Dwh7271]

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 47.484 grain H2O = 3.083 cm³
Cartridge O.A.L. L6: 2.890 inch = 73.41 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   93    39.59   2650    2291   50448   9494    100.0    1.315
-06.3   94    39.89   2667    2322   51569   9529    100.0    1.302
-05.6   94    40.19   2685    2353   52714   9562    100.0    1.289
-04.9   95    40.49   2702    2384   53884   9596    100.0    1.277  ! Near Maximum !
-04.2   96    40.79   2720    2414   55081   9629    100.0    1.264  ! Near Maximum !
-03.5   96    41.09   2737    2445   56305   9662    100.0    1.252  ! Near Maximum !
-02.8   97    41.39   2754    2476   57558   9695    100.0    1.240  ! Near Maximum !
-02.1   98    41.69   2772    2507   58840   9727    100.0    1.228  ! Near Maximum !
-01.4   98    41.99   2789    2539   60150   9759    100.0    1.216  ! Near Maximum !
-00.7   99    42.29   2806    2570   61491   9790    100.0    1.204  ! Near Maximum !
+00.0  100    42.59   2823    2601   62862   9822    100.0    1.193  !DANGEROUS LOAD-DO NOT USE!
+00.7  101    42.89   2840    2633   64264   9853    100.0    1.182  !DANGEROUS LOAD-DO NOT USE!
+01.4  101    43.19   2857    2664   65700   9883    100.0    1.171  !DANGEROUS LOAD-DO NOT USE!
+02.1  102    43.49   2874    2696   67170   9913    100.0    1.160  !DANGEROUS LOAD-DO NOT USE!
+02.8  103    43.79   2891    2727   68672   9943    100.0    1.149  !DANGEROUS LOAD-DO NOT USE!
+03.5  103    44.09   2908    2759   70214   9973    100.0    1.138  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba    100    42.59   2853    2657   66570   9696    100.0    1.167  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba    100    42.59   2789    2539   59276   9964    100.0    1.221  ! Near Maximum !

Cartridge          : 6.5 Creedmoor Hornady
Bullet             : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 47.830 grain H2O = 3.106 cm³
Cartridge O.A.L. L6: 2.915 inch = 74.04 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Alliant Reloder-16

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   92    39.59   2641    2277   49779   9526    100.0    1.323
-06.3   93    39.89   2659    2308   50879   9561    100.0    1.310
-05.6   94    40.19   2677    2338   52000   9595    100.0    1.297
-04.9   94    40.49   2694    2369   53148   9629    100.0    1.284
-04.2   95    40.79   2711    2399   54321   9663    100.0    1.272  ! Near Maximum !
-03.5   96    41.09   2729    2430   55522   9696    100.0    1.259  ! Near Maximum !
-02.8   96    41.39   2746    2461   56748   9729    100.0    1.247  ! Near Maximum !
-02.1   97    41.69   2763    2492   57980   9762    100.0    1.236  ! Near Maximum !
-01.4   98    41.99   2780    2523   59283   9794    100.0    1.224  ! Near Maximum !
-00.7   98    42.29   2797    2554   60596   9826    100.0    1.212  ! Near Maximum !
+00.0   99    42.59   2814    2585   61939   9858    100.0    1.200  ! Near Maximum !
+00.7  100    42.89   2831    2616   63312   9889    100.0    1.189  !DANGEROUS LOAD-DO NOT USE!
+01.4  101    43.19   2848    2648   64713   9920    100.0    1.178  !DANGEROUS LOAD-DO NOT USE!
+02.1  101    43.49   2865    2679   66152   9951    100.0    1.167  !DANGEROUS LOAD-DO NOT USE!
+02.8  102    43.79   2882    2711   67622   9982    100.0    1.156  !DANGEROUS LOAD-DO NOT USE!
+03.5  103    44.09   2899    2742   69128  10012    100.0    1.145  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     99    42.59   2844    2641   65596   9732    100.0    1.174  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba     99    42.59   2780    2522   58410  10000    100.0    1.229  ! Near Maximum !

 

[andrewctillman]

THANK YOU very much for taking the time to do that.

Almost no difference as Songdog said.

the proximity to my rifling must be making the difference. Or else my chronograph is all screwed up. But Hornady 140 BTHP, 140 ELD and 147 ELD reference ammo was indicating normal range.

I expect to chronograph again on Thursday or Sunday.

thanks to you both.

 

[andrewctillman]

Tikka T3x CTR (23 ¾ inch barrel w Surefire 6.8 mm brake). Surefire Suppressor attached. Once fired Hornady brass. Full length resized with 0.290 neck bushing. RL-16. Federal 210-M primer. 2.890 OCL. 75-83 degrees 3250 feet asl. 50% humidity. 30.0 Hg. 10-14 mph NW wind. 100 yards.

Here are results using QL guidance. It is very useful to have a velocity/pressure range to aim for even if the powder charges were 0.5 to 1.5 grains more than predicted to reach those velocities. You have saved me a lot of bench and range time. Many thanks!

Control group. 140 Hornady BTHP.
UP 1, LEFT 1 with suppressor.
2636, 2615, 2659 fps. (2636 average).

140 Nosler RDF.

42.5 grains, 2.915 OCL 2,753 fps
42.5 grains, 2.890 OCL, 2,771 fps (54,000 psi).
43.0 grains, 2.915 OCL, 2,822 fps. (57,000 psi).
*43.0 grains, 2.890 OCL, 2,805 fps (56,000). Use or try 43.2 gr.

About 90 fps slower and 1.3 gr more powder than QL predicted.
½ x ¾ inch group. (4)

140 Hornady ELD-M.

42.5 grains, 2.915 OCL, 2795 fps
42.5 grains, 2.890 OCL 2,806 fps (55,800)
43.0 grains, 2.915 OCL, 2,817 fps
*43.0 grains, 2.890 OCL 2,823 fps (57,000). Use.

About 50 fps slower and 0.7 gr more powder than QL predicted.
¼ x ¼ (3), called flyer.

147 Hornady ELD-M.

41.6 grains, 2.915 OCL, 2693 fps
42.0 grains, 2.915 OCL, 2715 fps.
42.5 grains, 2.915, 2,741 fps (56,000)
*42.5 grains, 2.890 OCL, 2734 fps (56,000)
*(42.7 grains, 2.890 OCL not tested but probably 2,750 fps, 57,600 psi.) Use?
43.0 grains, 2.915 OCL, 2781 (60,000 psi). Don’t use.

About 90 fps slower and 1.5 gr more powder than QL predicted.
¼ inch x 5/8 (5)

PS Pretty promising groups considering there was 0.5 to 1.4 grain spread in powder charges.

 

[Songdog]

How are you figuring your pressures?

 

[andrewctillman]

Songdog,

I compare my chronographed velocity with QL prediction of pressure at the same approximate velocity.

I stop testing powder charges that produce a chronographed velocity above 60,000 psi, and aim for something between 55 and 57,000.

 

[Songdog]

That seems very presumptive... and highly inaccurate.

What are you trying to accomplish with all this data collection? Are you not seeing accuracy/velocity where you’d like it to be? Are you trying to get the most velocity for the least powder or pressure?

 

[andrewctillman]

Most velocity at safe pressure.

 

[Songdog]

How do you know when you’ve reached “safe pressure”?

 

[andrewctillman]

Without QL data points I would probably keep pouring powder with both the 140 and 147 grain bullets. They "look" and "feel" safe.

My freind the late Bill Steigers developed the correlation between case head expansion and psii in the 1960's when he wrote the first five Speer reloading manuals.

That has fallen out of favor recently but is still useful.

PS Have you had any trouble with your CTR magazines?

 

[Songdog]

I’ve had no issues with the first generation magazines, I have a buddy with a T3x CTR in 6.5 Creed, and he’s had some troubles with his mag.

I’d step on the glass a little with the 140s, until you hit 2850.... unless you’re satisfied with the accuracy at 2800 with the 42/42.5 grain loads.

2700+ is pretty solid velocity for a 147 out of the Creed. I’d settle in around 42.5-43 grains and run them out to 5-600 or so.

In a 24” Creed I’d look for:
100s at 3100
123s at 2950
140s at 2850
147s at 2750