.280 Remington

[brdhntr]

The data for this round is based off of really low pressures, what are some of the hottest rounds you guys have loaded. I have gotten up to 57 grains of IMR 4350 with a 145gr bullet, but this is way beyond anything I have seen published. At this pressure I see about 1 in every 10 shots create a sticky bolt. Slightly flat primers, and polished marks on the brass against the bolt face are present. I'm still nervous about this round.

 

[gbp]

From QuickLoad
Cartridge : .280 Rem.
Bullet : .284, 145, Speer BTSP 1628
Cartridge O.A.L. L6: 3.330 inch or 84.58 mm
Barrel Length : 20.0 inch or 508.0 mm
Powder : IMR 4350

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 83 45.60 2296 1697 33073 10657 85.3 1.346
-18.0 85 46.74 2354 1783 35281 11032 86.6 1.310
-16.0 87 47.88 2412 1873 37607 11401 87.9 1.273
-14.0 89 49.02 2470 1965 40067 11764 89.2 1.234
-12.0 91 50.16 2529 2060 42686 12119 90.4 1.196
-10.0 94 51.30 2588 2157 45474 12464 91.5 1.160
-08.0 96 52.44 2647 2256 48443 12799 92.6 1.126
-06.0 98 53.58 2707 2359 51606 13123 93.6 1.092 ! Near Maximum !
-04.0 100 54.72 2766 2463 54979 13433 94.6 1.060 ! Near Maximum !
-02.0 102 55.86 2826 2570 58576 13729 95.4 1.028 !DANGEROUS LOAD-DO NOT USE!
+00.0 104 57.00 2885 2680 62416 14010 96.2 0.998 !DANGEROUS LOAD-DO NOT USE!
+02.0 106 58.14 2945 2792 66519 14274 97.0 0.969 !DANGEROUS LOAD-DO NOT USE!
+04.0 108 59.28 3004 2906 70907 14520 97.6 0.941 !DANGEROUS LOAD-DO NOT USE!
+06.0 110 60.42 3064 3023 75603 14747 98.2 0.914 !DANGEROUS LOAD-DO NOT USE!
+08.0 112 61.56 3124 3142 80637 14953 98.7 0.887 !DANGEROUS LOAD-DO NOT USE!
+10.0 114 62.70 3183 3263 86040 15137 99.1 0.862 !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 104 57.00 3026 2947 73508 14082 99.6 0.927 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 104 57.00 2705 2356 51601 13325 89.4 1.090 ! Near Maximum !

 

[gbp]

I have been told that most who handload for the 280 use 270 data. The 280 is also used in semi auto rifles as well therefore published data is normally low. That being said as indicated above the load you have stated exceeds the rec. psi

hope this helps

 

[brdhntr]

Thank you for the info . I'll backer down a little.

 

[jwcrabb]

Here is my load: 56.0 grns. RL-19
140 Nosler Accubond
COL 3.362
3/8" groups @ 100 out of T/C Encore

 

[JPH]

I don't know if this is useful or not but here goes: the SAAMI spec for a .270 is 54,000 PSI and the .280 spec is 50,000 PSI. The reason it is lower is the .280 was originally made for semi-automatic rifles with are not as strong as bolt actions. Many shooters I know give the .280 "another grain" to load her up to .270 pressures in bolt action rifles. If it's a pump or a semi-automatic action, stay below 50,000 PSI. The same is true of 30-06 also, 50,000 is usually the top load shown and I have done this with both 30-06 and .280 myself when reloading for these cartridges in modern bolt action rifles.

 

[Winchester 69]

i don't know if this is useful or not, but here goes: The saami spec for a .270 is 54,000 psi and the .280 spec is 50,000 psi.

c.u.p.?
.

 

[JPH]

C.U.P., yep, my bad!