6.5-284 loads?

[Bug Splat]

I have my load already but I just checkout the Hodgdon site and they now have some load data for this round in the H4350. Maybe they always had it but I just never noticed it before tonight. Anyway they say the max charge with a 140gr bullet is 45.5gr. I started at 46gr and worked my way all the way up through 49gr without any over pressure signs. I was following what Bill Shahane told me (he is a friend of a friend). I found my best groups at 46.5grs shooting sub 1/4 moa.

I was wondering what some of you load at. Hodgdon seems very very light on their charge weight. Could it be that I'm not getting over pressure signs because I'm seating a mile out (3.24 OAL)?

[Fjold]

I'm loading 46 grains of H4350 with the 142 grain SMK (3.02 OAL) for 2800 fps in my 26" barrel.

49 grains limits the Lapua brass to 2 reloads before the primer pockets are too loose to hold the primers in.

[Bug Splat]

I'm loading 46 grains of H4350 with the 142 grain SMK (3.02 OAL) for 2800 fps in my 26" barrel.

49 grains limits the Lapua brass to 2 reloads before the primer pockets are too loose to hold the primers in.

Awesome. That means we are right around the same pressure levels. I was worried I was floating in the danger zone but now I feel better.

[ar15barrels]

You guys are 3/16" different in your seating lengths.
That can be good for 1-2gr difference in charge to be at the same pressure level.

[ar15barrels]

I was wondering what some of you load at. Hodgdon seems very very light on their charge weight.
Could it be that I'm not getting over pressure signs because I'm seating a mile out (3.24 OAL)?

Yes.

Here's a quickload simulation of your load...

Cartridge          : 6.5-284 Norma
Bullet             : .264, 140, Berger VLD
Cartridge O.A.L. L6: 3.240 inch or 82.30 mm
Barrel Length      : 26.0 inch or 660.4 mm
Powder             : Hodgdon H4350

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.02% 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

-10.2   77    44.00   2616    2128   39051   9814     99.1    1.543
-09.2   78    44.50   2643    2171   40237   9904     99.3    1.521
-08.2   79    45.00   2669    2215   41451   9991     99.4    1.500
-07.1   80    45.50   2695    2258   42695  10074     99.6    1.480
-06.1   81    46.00   2721    2302   43972  10153     99.7    1.459
-05.1   82    46.50   2747    2346   45285  10229     99.8    1.440
-04.1   83    47.00   2773    2391   46635  10299     99.9    1.420
-03.1   84    47.50   2799    2435   48021  10366    100.0    1.401
-02.0   85    48.00   2825    2480   49446  10428    100.0    1.382
-01.0   85    48.50   2850    2525   50910  10486    100.0    1.364  ! Near Maximum !
+00.0   86    49.00   2875    2570   52415  10543    100.0    1.346  ! Near Maximum !
+01.0   87    49.50   2901    2615   53962  10599    100.0    1.328  ! Near Maximum !
+02.0   88    50.00   2926    2661   55551  10655    100.0    1.311  ! Near Maximum !
+03.1   89    50.50   2950    2706   57186  10710    100.0    1.294  ! Near Maximum !
+04.1   90    51.00   2975    2752   58865  10764    100.0    1.277  !DANGEROUS LOAD-DO NOT USE!
+05.1   91    51.50   3000    2797   60592  10817    100.0    1.260  !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     86    49.00   2910    2632   55276  10423    100.0    1.316  ! Near Maximum !
Data for burning rate decreased by 3% relative to nominal value:
-Ba     86    49.00   2836    2501   49562  10661     99.9    1.379

Here's the same simulation with the bullet seated to 3.040":

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-10.2   81    44.00   2668    2212   41847   9697     99.4    1.493
-09.2   82    44.50   2695    2257   43161   9779     99.5    1.472
-08.2   83    45.00   2721    2302   44508   9857     99.7    1.451
-07.1   84    45.50   2748    2348   45891   9931     99.8    1.431
-06.1   85    46.00   2775    2394   47313  10001     99.9    1.411
-05.1   85    46.50   2801    2440   48777  10067    100.0    1.392
-04.1   86    47.00   2828    2486   50283  10128    100.0    1.372
-03.1   87    47.50   2854    2532   51833  10184    100.0    1.353  ! Near Maximum !
-02.0   88    48.00   2880    2579   53429  10239    100.0    1.335  ! Near Maximum !
-01.0   89    48.50   2906    2625   55072  10292    100.0    1.317  ! Near Maximum !
+00.0   90    49.00   2932    2672   56763  10345    100.0    1.299  ! Near Maximum !
+01.0   91    49.50   2957    2719   58505  10398    100.0    1.282  ! Near Maximum !
+02.0   92    50.00   2983    2766   60298  10450    100.0    1.264  !DANGEROUS LOAD-DO NOT USE!
+03.1   93    50.50   3008    2813   62144  10501    100.0    1.248  !DANGEROUS LOAD-DO NOT USE!
+04.1   94    51.00   3034    2861   64046  10551    100.0    1.231  !DANGEROUS LOAD-DO NOT USE!
+05.1   95    51.50   3059    2908   66004  10601    100.0    1.215  !DANGEROUS LOAD-DO NOT USE!

The 0.200" difference in seating length is good for 5000 psi.

[Fjold]

I had my chamber cut with a shorter throat so that I could chase it a bit longer as it wears.

[BigBamBoo]

..........

[Bug Splat]

Thanks guys, awesome info. I had no idea that little difference in seating could have such a drastic difference. I expect no more than a 700-800psi difference.

I'm really going to have to pickup Quickload.

[Bug Splat]

GOOD LORD! Quickload is expensive! I was expecting $50 and had the CC out and ready. I'm going to have to save for that after I recover from Christmas bills.

Randall, I hate to ask but could you give my same load but with a 28" barrel? From what I read i should get a 30-40fps increase but i'm not sure if that holds true for my longer barrel. Everyone seem to compare 24"-26" or 22"-24".