Seating issues

[wisconsinteacher]

Tonight while seating 107 Sierra hpbt in my Grendel I had to seat them so they were compressed. This put presure on the bullet and put a small dent on the ogive. I used my hornady seating die. I was able to seat them but you can feel the dent. Have you ever heard of this? I loaded 7.62 fire formed brass with 28.5/29/29.5 grains of XBR8208. Did I over charge them? Kind of stumped here.

 

[DrMike]

QL indicates that you have a pretty hefty charge for the case. Yours has less case capacity than is allowed here. Formed from 7.62 brass, you will have somewhat thicker case walls reducing capacity still more.

Cartridge : 6.5 mm Grendel
Bullet : .264, 107, Sierra HPBT MatchK 1715 G7 Litz
Useable Case Capaci: 28.919 grain H2O = 1.878 cm³
Cartridge O.A.L. L6: 2.250 inch = 57.15 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : IMR 8208 XBR

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 86 22.80 2206 1156 30655 5344 88.0 1.385
-18.0 88 23.37 2260 1213 32727 5511 89.2 1.349
-16.0 90 23.94 2313 1271 34945 5674 90.4 1.313
-14.0 92 24.51 2366 1330 37319 5831 91.5 1.279
-12.0 94 25.08 2420 1391 39859 5984 92.5 1.242
-10.0 96 25.65 2473 1453 42580 6131 93.5 1.206
-08.0 98 26.22 2527 1517 45471 6271 94.4 1.171 ! Near Maximum !
-06.0 100 26.79 2580 1582 48555 6404 95.2 1.138 ! Near Maximum !
-04.0 103 27.36 2634 1648 51863 6530 96.0 1.106 !DANGEROUS LOAD-DO NOT USE!
-02.0 105 27.93 2687 1716 55415 6648 96.7 1.075 !DANGEROUS LOAD-DO NOT USE!
+00.0 107 28.50 2741 1784 59232 6758 97.3 1.045 !DANGEROUS LOAD-DO NOT USE!
+02.0 109 29.07 2794 1854 63341 6859 97.9 1.016 !DANGEROUS LOAD-DO NOT USE!
+04.0 111 29.64 2847 1926 67769 6950 98.4 0.988 !DANGEROUS LOAD-DO NOT USE!
+06.0 113 30.21 2900 1998 72548 7031 98.9 0.961 !DANGEROUS LOAD-DO NOT USE!
+08.0 115 30.78 2953 2072 77715 7102 99.2 0.935 !DANGEROUS LOAD-DO NOT USE!
+10.0 118 31.35 3006 2147 83313 7162 99.5 0.910 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 107 28.50 2862 1946 70475 6658 99.9 0.975 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 107 28.50 2579 1580 48393 6548 91.1 1.136 ! Near Maximum !

 

[wisconsinteacher]

I will take them apart and start over. So the next question, is the powder wasted after being compressed so much?

 

[wisconsinteacher]

I can't believe there is that much difference in the brass. I took my weight charges off the Hodgen webpage.

 

[JD338]

You might want to back down on the charge weight. Have you shot this load with this brass in the past?

JD338

 

[wisconsinteacher]

No, I have not shot it. I just got the bullets. I have used 129 SST bullets with 26.6 grains of XBR8208

 

[Oldtrader3]

You can salvage the powder. Being compressed slightly will not harm most grains of the powder and the powder can be reloaded.

 

[DrMike]

Cartridge : 6.5 mm Grendel
Bullet : .264, 129, Hornady SST InterLock 26202
Useable Case Capaci: 27.395 grain H2O = 1.779 cm³
Cartridge O.A.L. L6: 2.250 inch = 57.15 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : IMR 8208 XBR

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 82 20.80 2000 1146 30831 5086 91.1 1.516
-18.0 84 21.32 2047 1200 32859 5235 92.1 1.477
-16.0 86 21.84 2093 1255 35012 5379 93.1 1.439
-14.0 89 22.36 2140 1312 37285 5518 94.0 1.402
-12.0 91 22.88 2186 1369 39689 5652 94.9 1.363
-10.0 93 23.40 2233 1428 42251 5779 95.7 1.325
-08.0 95 23.92 2279 1488 44981 5901 96.4 1.289 ! Near Maximum !
-06.0 97 24.44 2325 1548 47893 6016 97.1 1.254 ! Near Maximum !
-04.0 99 24.96 2371 1610 51001 6124 97.7 1.220 ! Near Maximum !
-02.0 101 25.48 2417 1673 54320 6225 98.2 1.187 !DANGEROUS LOAD-DO NOT USE!
+00.0 103 26.00 2462 1737 57867 6317 98.6 1.156 !DANGEROUS LOAD-DO NOT USE!
+02.0 105 26.52 2508 1801 61662 6402 99.0 1.125 !DANGEROUS LOAD-DO NOT USE!
+04.0 107 27.04 2553 1867 65727 6477 99.4 1.096 !DANGEROUS LOAD-DO NOT USE!
+06.0 109 27.56 2598 1933 70086 6544 99.6 1.068 !DANGEROUS LOAD-DO NOT USE!
+08.0 111 28.08 2643 2001 74766 6602 99.8 1.040 !DANGEROUS LOAD-DO NOT USE!
+10.0 113 28.60 2688 2069 79799 6649 99.9 1.014 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 103 26.00 2560 1877 68541 6123 100.0 1.082 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 26.00 2327 1551 47529 6218 93.5 1.253 ! Near Maximum !

That is a different bullet and a quantitatively different charge. Even so, QL projects this to be a higher pressure. JD338 and Fotis have offered good advice to start low and work up. Your rifle is unique and needs to work within its own pressure limits.

 

[wisconsinteacher]

Thanks for the help. As of now, I don't have any rounds made up other than the ones I made tonight so I will double check everything and restart the process.

That was not 129 SST but 123 Amax bullets sorry.