280 ai speed

[chad]

Not getting the speed out of my 280ai with 140 ttsx and h4831sc. 24" barrel.

What powder next?

 

[Ridgerunner665]

Top 20 from QuickLoad...what speed are you getting?


Norma MRP 104.3 65.7 4.26 3225 99.6 63000 12920 1.097 ! Near Maximum !
IMR 7828 SSC 104.5 64.8 4.20 3195 97.7 63000 12705 1.086 ! Near Maximum !
Vihtavuori N560 105.0 64.8 4.20 3179 96.9 60919 13021 1.110 ! Near Maximum !
Alliant Reloder-17 93.6 59.3 3.84 3171 100.0 63000 11438 1.098 ! Near Maximum !
ADI AR 2213 105.0 64.1 4.15 3166 97.4 62142 12534 1.092 ! Near Maximum !
Alliant Reloder-22 105.0 64.1 4.15 3150 98.4 60449 12569 1.120 ! Near Maximum !
ADI AR 2209 102.3 61.4 3.98 3146 98.6 63000 12003 1.090 ! Near Maximum !
Alliant Reloder-19 102.9 62.1 4.02 3143 98.6 63000 12072 1.099 ! Near Maximum !
Ramshot Hunter 98.3 61.3 3.97 3141 99.9 63000 11746 1.105 ! Near Maximum !
Hodgdon H414 92.9 59.3 3.84 3138 99.6 63000 11782 1.106 ! Near Maximum !
Winchester 760 92.9 59.3 3.84 3138 99.6 63000 11782 1.106 ! Near Maximum !
Norma URP 97.9 58.5 3.79 3121 100.0 63000 11261 1.111 ! Near Maximum !
Vihtavuori N550 95.1 58.7 3.80 3120 100.0 63000 11397 1.115 ! Near Maximum !
Norma 204 97.5 60.8 3.94 3117 98.4 63000 11755 1.100 ! Near Maximum !
Accurate 4350 97.0 58.6 3.79 3115 100.0 63000 11223 1.128 ! Near Maximum !
Hodgdon H4831 SC 104.0 63.5 4.11 3113 96.8 63000 11837 1.096 ! Near Maximum !
IMR 4831 102.7 59.4 3.85 3101 100.0 63000 11014 1.120 ! Near Maximum !
Winchester Supreme 780 101.3 64.5 4.18 3090 98.5 63000 11439 1.104 ! Near Maximum !
Hodgdon Hybrid 100V 100.5 58.7 3.80 3079 100.0 63000 10377 1.111 ! Near Maximum !
Hodgdon H4350 100.3 59.2 3.84 3079 99.2 63000 11148 1.105 ! Near Maximum !

 

[chad]

RIdge, im loading 61 grains of H4831sc with the 140 gr. TTSX and getting 3083-3100fps.

I was hoping to get close to the 3200 fps range. Right now im shooting the same speeds I was with the original 280 with 58 grains of rl19 and 140 accubonds.
So going to the Ackley didn't do me any good as of yet.

 

[Ridgerunner665]

4831 is too fast burning for top speed from a 280AI...

You'll need 7828ssc or MRP to reach anywhere near 3,200 fps...and thats not just based on QuickLoad....thats based on fact.

Reloder 22 is worth a try too...may not quite get you there, but it will get you close...

To use the extra capacity of the Ackley....you have to use slow burning powders...then you'll see some speed.

 

[chad]

Ill try the 7828ssc I have.

Maybe h4350? I just want a temp stable powder. Is rl22 temp stable? rl25?
I have a pound of retumbo I could try also.

 

[Ridgerunner665]

Cartridge          : .280 Ack Imp
Bullet             : .284, 140, Barnes 'TTSX'BT 28474
Useable Case Capaci: 65.489 grain H2O = 4.252 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Norma MRP

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.758% 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

-07.6   97    61.00   2979    2759   48753  12234     97.6    1.233
-06.8   98    61.50   3006    2808   50086  12323     97.9    1.218
-06.1   98    62.00   3032    2858   51458  12409     98.1    1.203
-05.3   99    62.50   3058    2907   52872  12491     98.4    1.188
-04.5  100    63.00   3085    2958   54335  12569     98.6    1.173
-03.8  101    63.50   3111    3008   55841  12643     98.9    1.158  ! Near Maximum !
-03.0  102    64.00   3137    3059   57395  12714     99.1    1.144  ! Near Maximum !
-02.3  102    64.50   3163    3111   58999  12780     99.2    1.130  ! Near Maximum !
-01.5  103    65.00   3190    3163   60653  12842     99.4    1.116  ! Near Maximum !
-00.8  104    65.50   3216    3215   62363  12900     99.6    1.102  ! Near Maximum !
+00.0  105    66.00   3242    3267   64126  12953     99.7    1.088  ! Near Maximum !


Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba    105    66.00   3326    3439   71600  12695    100.0    1.041  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    105    66.00   3140    3065   57134  12999     98.0    1.142  ! Near Maximum !

 

[Ridgerunner665]

4350 is even faster than 4831...you'll lose some speed, not much, but a little.

 

[Ridgerunner665]

Cartridge          : .280 Ack Imp
Bullet             : .284, 140, Barnes 'TTSX'BT 28474
Useable Case Capaci: 65.489 grain H2O = 4.252 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : IMR 7828 SSC

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.769% 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

-07.7   97    60.00   2934    2676   48475  11806     94.2    1.226
-06.9   98    60.50   2961    2726   49799  11913     94.6    1.210
-06.2   98    61.00   2988    2776   51157  12018     95.0    1.195
-05.4   99    61.50   3016    2827   52565  12119     95.4    1.180
-04.6  100    62.00   3043    2878   54013  12218     95.8    1.165
-03.8  101    62.50   3070    2930   55493  12313     96.2    1.151  ! Near Maximum !
-03.1  102    63.00   3097    2982   57048  12405     96.5    1.136  ! Near Maximum !
-02.3  102    63.50   3125    3035   58638  12493     96.9    1.122  ! Near Maximum !
-01.5  103    64.00   3152    3088   60280  12578     97.2    1.108  ! Near Maximum !
-00.8  104    64.50   3179    3142   61976  12659     97.5    1.094  ! Near Maximum !
+00.0  105    65.00   3207    3196   63727  12737     97.8    1.080  ! Near Maximum !

 

[chad]

Thanks Ridge!! I appreciate your help.

 

[Ridgerunner665]

None of Hodgdens Extreme powders will run the Ackley to its full potential....none have the right burn characteristics.

 

[Ridgerunner665]

You're welcome...but be careful with that load data...work up, and be safe....a few FPS ain't worth a trip to the ER.

 

[chad]

I'll be careful, I'll work up slow and see what I get. Bad thing is I am getting super groups with the h4831.

 

[varmintH8R]

I'll be careful, I'll work up slow and see what I get. Bad thing is I am getting super groups with the h4831.

Not trying to be combative, but why chase 100FPS if accuracy is great?

 

[chad]

I'm keeping this load but will search for something a little faster. If I can get a faster accurate load great! If not I have one shooting good now.