Need some H-110 max load data for TL309-230-5R in 300 Blackout

[Jayhawkhuntclub]

On the Hodgdon site there is some 220-230 gr jacketed data that is there for sub-sonic loads. Based on that, I think it's safe to assume that 10.0 gr is a safe starting point. But where to go from there? :mrgreen: BTW, these are hard cast, water dropped bullets with a BNL harness in the upper teens. And they are dropping at 223 grains. Thanks!

[Moonie]

Somewhere in the 12.5gr range would probably be max, do be careful and watch for swipes and flattened primers. Personally I prefer RL-7 for the heavies and keep H110/W296 for the 155gr loads.

[Boolseye]

Personally, I go to where the gun cycles and call it good.
with the lee 309-230 in my carbine, this is 12.5 gr. RL 7.

[lar45]

Do you have the bullet length and the loaded length? If so, I can run it through Quickload.
Just guessing with a 222gn bullet with 16gn H110 should give 50k and go 1730fps ish.

[Jayhawkhuntclub]

Thank you Lar45!
Bullet length is 1.371" Let's call the OAL at 2.2 to be safe (I haven't actually finished building the gun yet).

[1johnlb]

If memory serves correctly, I think I was flattening primers at 9 grs with the Lee 230's, and stopped there. As the others said be careful.

[Jayhawkhuntclub]

9 gr seems pretty light to my estimation. Of course, I've been wrong before. Maybe I need to back off my starting load. BTW, what primers were you using John? I know those RP and Winchester primers tend to be pretty soft.

[1johnlb]

Cci and or tula 223. Can't remember exactly which one but I think they were the 400 sr which both of these caused random slam fires.
That was thru a pistol with a heavy buffer.
I was flattening primers with the Lee 155 at 16.5 ~17 grs, if memory serves me correctly.
Don't have my notes in front of me either, sorry. It's easier to increase your charge later than to after a doctor visit or a new build.
Good luck

[lar45]

Heres what Quickload spit out. Remember this is not load data, just a computer simulation.
One thing that bothers me is the fill percentage. The max load is only at 90% filled. So would it even be safe to load a lighter amount?
Anybody with experience please impart some knowledge for us.

Cartridge : .300 AAC Blackout
Bullet : .310, 230, .823 nose
Useable Case Capaci: 14.977 grain H2O = 0.972 cm³
Cartridge O.A.L. L6: 2.200 inch = 55.88 mm
Barrel Length : 20.0 inch = 508.0 mm
Powder : Hodgdon H110
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 72 10.64 1283 840 26405 2141 99.0 1.897
-18.0 74 10.91 1309 876 28231 2181 99.4 1.845
-16.0 75 11.17 1336 911 30162 2217 99.6 1.796
-14.0 77 11.44 1362 947 32204 2251 99.8 1.749
-12.0 79 11.70 1387 983 34363 2281 100.0 1.705
-10.0 81 11.97 1412 1019 36648 2308 100.0 1.662
-08.0 83 12.24 1437 1055 39066 2333 100.0 1.622
-06.0 84 12.50 1462 1091 41625 2357 100.0 1.583
-04.0 86 12.77 1486 1128 44335 2381 100.0 1.546 ! Near Maximum !
-02.0 88 13.03 1510 1164 47207 2405 100.0 1.510 ! Near Maximum !
+00.0 90 13.30 1533 1201 50250 2428 100.0 1.476 !DANGEROUS LOAD-DO NOT USE!
+02.0 92 13.57 1557 1238 53479 2450 100.0 1.443 !DANGEROUS LOAD-DO NOT USE!
+04.0 93 13.83 1580 1275 56906 2473 100.0 1.412 !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 90 13.30 1570 1259 60259 2321 100.0 1.400 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 90 13.30 1476 1112 40466 2573 99.6 1.586

[Jayhawkhuntclub]

Well thanks for all the help. I don't know what to think.:veryconfu I'm considering starting at 9.0 and working up.

Hodgdon lists this for a 220 gr Sierra HPBT:
H110 .308" 2.260" 9.9gr 1,050 fps 29,700 CUP
I know it's not a perfect apples to apples comparison. But it seems like it's not a totally unreasonable comparison for a hard cast boat tail bullet. Just don't know.