280 Ackley Improved Load ?

[Professionalhunter1]

Since there isn't that much published information about loading for the 280 Ackley from the bullet mfg.How much over the standard 280 Remington loads can you go 4%,5%,6% or 7% ?
For example Barnes list a max. load for their 160 grn bullet at 57 grains of H 1000 so with 7% added it would be 60.99 if figured at 7%?
The rifle being used is a Remington 700 with a Pac-Nor 26'super grade match barrel squared and blue printed action.
Any information will gladly be appreciated on this matter.
Thank you.

 

[gbp]

according to ql i do not see max until 64.53grns

Cartridge : .280 Ack Imp
Bullet : .284, 160, Barnes 'TSX' 28446
Useable Case Capaci: 64.223 grain H2O = 4.170 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.59 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon H1000

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 88 51.62 2327 1924 29118 8536 87.2 1.681
-18.0 90 52.91 2390 2030 31142 8848 88.8 1.635
-16.0 93 54.21 2454 2139 33323 9151 90.3 1.590
-14.0 95 55.50 2518 2253 35678 9442 91.7 1.546
-12.0 97 56.79 2583 2371 38222 9719 93.1 1.502
-10.0 99 58.08 2649 2493 40976 9980 94.3 1.459
-08.0 101 59.37 2715 2619 43959 10224 95.5 1.417
-06.0 104 60.66 2781 2748 47198 10448 96.5 1.371
-04.0 106 61.95 2848 2882 50719 10650 97.4 1.326 ! Near Maximum !
-02.0 108 63.24 2915 3019 54554 10830 98.2 1.282 ! Near Maximum !
+00.0 110 64.53 2982 3159 58739 10984 98.8 1.240 !DANGEROUS LOAD-DO NOT USE!
+02.0 112 65.82 3049 3303 63322 11111 99.3 1.198 !DANGEROUS LOAD-DO NOT USE!
+04.0 115 67.11 3116 3450 68347 11209 99.7 1.158 !DANGEROUS LOAD-DO NOT USE!
+06.0 117 68.40 3183 3600 73873 11277 99.9 1.119 !DANGEROUS LOAD-DO NOT USE!
+08.0 119 69.69 3250 3753 79970 11313 100.0 1.082 !DANGEROUS LOAD-DO NOT USE!
+10.0 121 70.98 3317 3909 86718 11327 100.0 1.045 !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 110 64.53 3136 3494 71419 10577 100.0 1.142 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 110 64.53 2767 2719 47768 10637 92.0 1.365

 

[Ackman]

For about any cartridge you can look in 5 different manuals and get 5 different max loads. Some are more conservative than others. But they all use a different test setup and load combination so trying to correlate one to another doesn't accomplish much.
The Nosler and Sierra manuals have .280AI. Sierra is conservative. Don't worry about percentages. If you're fireforming, work up a load as with any other cartridge. This means trying different powder and bullets. Start someplace near max for the parent cartridge but enough below to where you're comfortable. Then go up - keeping an eye on signs of overpressure - 'til you find the best accuracy. Fireforming loads will be as accurate as loads using formed brass. With formed cases the load will be very close to the same as with fireforming, or just a little more.

 

[Professionalhunter1]

Thank you for the info, I guess I was figuring on the low side so I'll try your info out and see what happens .

 

[bingo1010]

for information i shoot a rem action 28' krieger barrel with 162 a max and 4831sc to a load of 60.5gr. this is with nosler brass. gives a speed of 2990fps. this is by no means high pressure in my rifle, but then again with the straight wall ackley type cartridges visual pressure signs do not show up as in normal cases.

 

[280Ackleyrized]

Here is a good one for you. The load was originally developed by a gentleman in Memphis, TN. Jim Borden gives out this same load with the 280AI rifles he builds. VV N165, Fed Gold Medal Match LR primer, 140NAB. Did 3206fps from my rifle out of a 24 3/4 Hart #5 barrel with groups running in the .3s for 5 shots. Lots of folks on the campfire have tried this load with excellent results and it seems to be liked by most rifles chambered in 280AI. My powder weight is 63.3 grains, but i would reccomend backing off a bit and working back up. YMMV

 

[seymour fish]

Since there isn't that much published information about loading for the 280 Ackley from the bullet mfg.How much over the standard 280 Remington loads can you go 4%,5%,6% or 7% ?
For example Barnes list a max. load for their 160 grn bullet at 57 grains of H 1000 so with 7% added it would be 60.99 if figured at 7%?
The rifle being used is a Remington 700 with a Pac-Nor 26'super grade match barrel squared and blue printed action.
Any information will gladly be appreciated on this matter.
Thank you.

At least with the original Barnes X, seating a minimum of .050 Off the lands was stressed. Experience with those dictated reigning in velocity to keep pressure acceptable. Barnes manual seemed "optimistic" re: achievable MV.