260 AI. Anybody ever play with one?
- Thread starter jmad_81
- Start date
- Nov 4, 2004
- 25,677
- 10,018
Jake,
The 260 Rem is pretty good as is.
If you want more from the short action, look at a magnum bolt face and chamber a 6.5mm Reg Mag.
Pretty cool round and it runs with the 6.5mm-06 and the 6.5-284.
JD338
The 260 Rem is pretty good as is.
If you want more from the short action, look at a magnum bolt face and chamber a 6.5mm Reg Mag.
Pretty cool round and it runs with the 6.5mm-06 and the 6.5-284.
JD338
- Thread starter
- #23
muleman":1lxubmd9 said:
I'm pretty sure Darrin has a 243 AI reamer :idea: I could set it back an inch, and get a new set of dies for less than I could get just the barrel for a 6.5 anything. Not a bad idea. Thanks! Plus it would give me some more life to shoot the small mountain of 6mm bullets I have stashed up.
Woodycreek
Handloader
- Aug 2, 2007
- 2,240
- 0
jmad_81":11xcbswp said:
Sweet!!!
Pretty sure a lot of extra speed comes from more pressure out of AI'ed cartridges then the extra powder space. You can't equate 10% increase in powder space, which is pretty generous to 150-200 FPS with everything being equal. The extra capacity of the case doesn't add up. I could be way off, but I haven't seen huge gains by AI'ing. I'm betting if the parent cartridge was loaded to equal specs in the same rifle the results wouldn't be quite as far apart. Not knocking them, as they look cool, but besides minimalizing trimming the parent is pretty close to the same, equally loaded.
The big gains were the H&H blown out to Weatherby case and others, but with today's powders and today's tighter specs trimming is even less of an issue.
The big gains were the H&H blown out to Weatherby case and others, but with today's powders and today's tighter specs trimming is even less of an issue.
- Thread starter
- #27
Depeding on what you are wanting to do with it, I like the 280 AI over the 270 WSM. I have had both, and still have the 280 AI, and no 270 WSM. The 280 AI just seemed easier to load for. I don't know about bullet selection as the .277 cals are starting to get some pretty dang good bullets. I just like the case better I guess. Really though, its six of one, half dozen of the other.
A 270WSM or 7mm WSM will both provide a lot of speed easily without having to push them over 65K Dan. When i get back to my laptop I will run a QL profile. Granted it isn't everything, but as Jim says, there's no replacement for displacement. The WSMs have that in spades in the 7mm and 270.
DrMike
Ballistician
- Nov 8, 2006
- 37,589
- 6,757
sask boy":36iqhntr said:
Either will serve you well, Dan. The 280AI has the intangible of "cool." Ammunition can always be created from 280 rounds in a pinch. Bullet selection may be slightly better in the .284 round. That is not merely damning the 270WSM with faint praise. As you know, my 270WSM has accounted for multiple elk and moose; it will get the job done. Then, again, the 280AI will accomplish pretty much the same thing.
The 150 BT out of the 270WSM with RL33
Cartridge : .270 WSM
Bullet : .277, 150, Nosler BalTip 39588
Useable Case Capaci: 70.966 grain H2O = 4.608 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder 33
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 69.89 2800 2611 42661 13648 91.8 1.410
-09.0 98 70.66 2839 2685 44376 13848 92.6 1.383
-08.0 99 71.44 2879 2761 46172 14040 93.3 1.357
-07.0 100 72.21 2919 2838 48055 14226 94.0 1.332
-06.0 102 72.99 2959 2916 50027 14404 94.7 1.306
-05.0 103 73.77 2999 2996 52096 14574 95.3 1.282
-04.0 104 74.54 3040 3077 54268 14736 95.9 1.257 ! Near Maximum !
-03.0 105 75.32 3080 3160 56547 14890 96.5 1.233 ! Near Maximum !
-02.0 106 76.10 3121 3244 58943 15034 97.0 1.210 ! Near Maximum !
-01.0 107 76.87 3161 3329 61461 15168 97.5 1.187 ! Near Maximum !
+00.0 108 77.65 3202 3415 64112 15293 97.9 1.164 !DANGEROUS LOAD-DO NOT USE!
+01.0 109 78.43 3243 3503 66901 15407 98.3 1.142 !DANGEROUS LOAD-DO NOT USE!
+02.0 110 79.20 3284 3592 69840 15510 98.7 1.120 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 79.98 3325 3683 72940 15602 99.0 1.098 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 80.76 3366 3774 76211 15683 99.3 1.077 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 81.53 3407 3867 79654 15751 99.5 1.056 !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 108 77.65 3399 3848 81488 14917 100.0 1.056 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 77.65 2933 2865 49584 14521 89.7 1.304
7WSM 160 AB RL33
Cartridge : 7 mm WSM
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 71.082 grain H2O = 4.615 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder 33
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 69.89 2713 2615 40464 12965 90.5 1.449
-09.0 98 70.66 2751 2689 42065 13164 91.3 1.422
-08.0 99 71.44 2790 2766 43740 13357 92.1 1.396
-07.0 100 72.21 2829 2843 45494 13544 92.8 1.370
-06.0 101 72.99 2868 2923 47332 13725 93.5 1.344
-05.0 102 73.77 2907 3003 49258 13899 94.2 1.319
-04.0 104 74.54 2947 3085 51279 14066 94.9 1.294
-03.0 105 75.32 2987 3169 53399 14224 95.5 1.269
-02.0 106 76.10 3026 3254 55624 14375 96.0 1.245 ! Near Maximum !
-01.0 107 76.87 3066 3340 57965 14517 96.6 1.222 ! Near Maximum !
+00.0 108 77.65 3106 3428 60424 14650 97.1 1.198 ! Near Maximum !
+01.0 109 78.43 3146 3517 63012 14774 97.6 1.176 ! Near Maximum !
+02.0 110 79.20 3187 3608 65736 14888 98.0 1.153 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 79.98 3227 3700 68607 14992 98.4 1.131 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 80.76 3267 3793 71634 15086 98.7 1.109 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 81.53 3308 3888 74831 15168 99.0 1.088 !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 108 77.65 3307 3886 76961 14429 100.0 1.086 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 77.65 2837 2859 46962 13760 88.1 1.343
280 AI 160 AB VN560
Cartridge : .280 Ack Imp
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 64.314 grain H2O = 4.176 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Vihtavuori N560
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 95 57.25 2746 2679 46202 11951 94.9 1.333
-09.0 96 57.89 2778 2743 47836 12093 95.4 1.311
-08.0 97 58.52 2811 2807 49532 12231 95.9 1.290
-07.0 98 59.16 2844 2873 51290 12364 96.4 1.269
-06.0 99 59.79 2876 2939 53121 12492 96.8 1.249
-05.0 100 60.43 2909 3006 55020 12615 97.2 1.229
-04.0 101 61.07 2941 3073 56994 12732 97.6 1.210 ! Near Maximum !
-03.0 102 61.70 2974 3142 59045 12844 97.9 1.190 ! Near Maximum !
-02.0 103 62.34 3006 3211 61176 12950 98.3 1.171 ! Near Maximum !
-01.0 104 62.97 3039 3280 63392 13051 98.6 1.153 ! Near Maximum !
+00.0 105 63.61 3071 3351 65685 13145 98.8 1.134 !DANGEROUS LOAD-DO NOT USE!
+01.0 106 64.25 3103 3422 68060 13233 99.1 1.117 !DANGEROUS LOAD-DO NOT USE!
+02.0 107 64.88 3136 3493 70526 13314 99.3 1.099 !DANGEROUS LOAD-DO NOT USE!
+03.0 108 65.52 3168 3566 73089 13389 99.5 1.082 !DANGEROUS LOAD-DO NOT USE!
+04.0 109 66.15 3200 3639 75748 13457 99.6 1.065 !DANGEROUS LOAD-DO NOT USE!
+05.0 110 66.79 3232 3712 78524 13518 99.8 1.048 !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 105 63.61 3217 3678 79916 12740 100.0 1.047 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 63.61 2868 2921 52451 12803 92.9 1.250
280 Rem 160 AB RL22
Cartridge : .280 Rem.
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 58.200 grain H2O = 3.779 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-22
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 95 51.26 2574 2354 40536 10404 94.2 1.408
-09.0 96 51.82 2605 2411 41937 10534 94.7 1.385
-08.0 97 52.39 2636 2468 43392 10661 95.2 1.363
-07.0 98 52.96 2666 2525 44901 10783 95.7 1.342
-06.0 99 53.53 2697 2584 46467 10902 96.2 1.321
-05.0 100 54.10 2728 2643 48091 11017 96.6 1.300
-04.0 101 54.67 2758 2703 49784 11127 97.0 1.279
-03.0 102 55.24 2789 2763 51537 11233 97.4 1.259
-02.0 103 55.81 2820 2824 53349 11335 97.8 1.239
-01.0 104 56.38 2850 2886 55258 11431 98.1 1.220 ! Near Maximum !
+00.0 105 56.95 2881 2949 57230 11522 98.4 1.201 ! Near Maximum !
+01.0 106 57.52 2912 3012 59281 11609 98.7 1.182 ! Near Maximum !
+02.0 107 58.09 2942 3075 61415 11690 98.9 1.163 ! Near Maximum !
+03.0 108 58.66 2973 3140 63636 11765 99.2 1.145 ! Near Maximum !
+04.0 109 59.23 3003 3205 65948 11835 99.4 1.128 !DANGEROUS LOAD-DO NOT USE!
+05.0 110 59.80 3034 3270 68348 11899 99.5 1.110 !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 105 56.95 3027 3254 70128 11226 100.0 1.106 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 56.95 2682 2555 45739 11130 91.9 1.324
All ran with the same pressure of 65K max. All of them do about the same, with the edge going to the 7mm WSM overall.
Looking at the AI vs the standard 280 nets about 75 FPS, which seems to be about standard, loaded the same.
Sorry to get off track, but there isn't much magic left in ballistics. Faster barrels, tighter chamber's, etc change things a little, but overall, the numbers don't lie too much.
Oh, also, QL shows about 6 grains overall difference between the AI and standard 280, so just about right on with the 10% gain on case capacity. Granted it's all reference, but I think alot of AI's get pushed to higher pressures as they seem to show less signs of excess pressure, so they get pushed harder..
Cartridge : .270 WSM
Bullet : .277, 150, Nosler BalTip 39588
Useable Case Capaci: 70.966 grain H2O = 4.608 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder 33
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 69.89 2800 2611 42661 13648 91.8 1.410
-09.0 98 70.66 2839 2685 44376 13848 92.6 1.383
-08.0 99 71.44 2879 2761 46172 14040 93.3 1.357
-07.0 100 72.21 2919 2838 48055 14226 94.0 1.332
-06.0 102 72.99 2959 2916 50027 14404 94.7 1.306
-05.0 103 73.77 2999 2996 52096 14574 95.3 1.282
-04.0 104 74.54 3040 3077 54268 14736 95.9 1.257 ! Near Maximum !
-03.0 105 75.32 3080 3160 56547 14890 96.5 1.233 ! Near Maximum !
-02.0 106 76.10 3121 3244 58943 15034 97.0 1.210 ! Near Maximum !
-01.0 107 76.87 3161 3329 61461 15168 97.5 1.187 ! Near Maximum !
+00.0 108 77.65 3202 3415 64112 15293 97.9 1.164 !DANGEROUS LOAD-DO NOT USE!
+01.0 109 78.43 3243 3503 66901 15407 98.3 1.142 !DANGEROUS LOAD-DO NOT USE!
+02.0 110 79.20 3284 3592 69840 15510 98.7 1.120 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 79.98 3325 3683 72940 15602 99.0 1.098 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 80.76 3366 3774 76211 15683 99.3 1.077 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 81.53 3407 3867 79654 15751 99.5 1.056 !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 108 77.65 3399 3848 81488 14917 100.0 1.056 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 77.65 2933 2865 49584 14521 89.7 1.304
7WSM 160 AB RL33
Cartridge : 7 mm WSM
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 71.082 grain H2O = 4.615 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder 33
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 69.89 2713 2615 40464 12965 90.5 1.449
-09.0 98 70.66 2751 2689 42065 13164 91.3 1.422
-08.0 99 71.44 2790 2766 43740 13357 92.1 1.396
-07.0 100 72.21 2829 2843 45494 13544 92.8 1.370
-06.0 101 72.99 2868 2923 47332 13725 93.5 1.344
-05.0 102 73.77 2907 3003 49258 13899 94.2 1.319
-04.0 104 74.54 2947 3085 51279 14066 94.9 1.294
-03.0 105 75.32 2987 3169 53399 14224 95.5 1.269
-02.0 106 76.10 3026 3254 55624 14375 96.0 1.245 ! Near Maximum !
-01.0 107 76.87 3066 3340 57965 14517 96.6 1.222 ! Near Maximum !
+00.0 108 77.65 3106 3428 60424 14650 97.1 1.198 ! Near Maximum !
+01.0 109 78.43 3146 3517 63012 14774 97.6 1.176 ! Near Maximum !
+02.0 110 79.20 3187 3608 65736 14888 98.0 1.153 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 79.98 3227 3700 68607 14992 98.4 1.131 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 80.76 3267 3793 71634 15086 98.7 1.109 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 81.53 3308 3888 74831 15168 99.0 1.088 !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 108 77.65 3307 3886 76961 14429 100.0 1.086 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 77.65 2837 2859 46962 13760 88.1 1.343
280 AI 160 AB VN560
Cartridge : .280 Ack Imp
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 64.314 grain H2O = 4.176 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Vihtavuori N560
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 95 57.25 2746 2679 46202 11951 94.9 1.333
-09.0 96 57.89 2778 2743 47836 12093 95.4 1.311
-08.0 97 58.52 2811 2807 49532 12231 95.9 1.290
-07.0 98 59.16 2844 2873 51290 12364 96.4 1.269
-06.0 99 59.79 2876 2939 53121 12492 96.8 1.249
-05.0 100 60.43 2909 3006 55020 12615 97.2 1.229
-04.0 101 61.07 2941 3073 56994 12732 97.6 1.210 ! Near Maximum !
-03.0 102 61.70 2974 3142 59045 12844 97.9 1.190 ! Near Maximum !
-02.0 103 62.34 3006 3211 61176 12950 98.3 1.171 ! Near Maximum !
-01.0 104 62.97 3039 3280 63392 13051 98.6 1.153 ! Near Maximum !
+00.0 105 63.61 3071 3351 65685 13145 98.8 1.134 !DANGEROUS LOAD-DO NOT USE!
+01.0 106 64.25 3103 3422 68060 13233 99.1 1.117 !DANGEROUS LOAD-DO NOT USE!
+02.0 107 64.88 3136 3493 70526 13314 99.3 1.099 !DANGEROUS LOAD-DO NOT USE!
+03.0 108 65.52 3168 3566 73089 13389 99.5 1.082 !DANGEROUS LOAD-DO NOT USE!
+04.0 109 66.15 3200 3639 75748 13457 99.6 1.065 !DANGEROUS LOAD-DO NOT USE!
+05.0 110 66.79 3232 3712 78524 13518 99.8 1.048 !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 105 63.61 3217 3678 79916 12740 100.0 1.047 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 63.61 2868 2921 52451 12803 92.9 1.250
280 Rem 160 AB RL22
Cartridge : .280 Rem.
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 58.200 grain H2O = 3.779 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-22
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 95 51.26 2574 2354 40536 10404 94.2 1.408
-09.0 96 51.82 2605 2411 41937 10534 94.7 1.385
-08.0 97 52.39 2636 2468 43392 10661 95.2 1.363
-07.0 98 52.96 2666 2525 44901 10783 95.7 1.342
-06.0 99 53.53 2697 2584 46467 10902 96.2 1.321
-05.0 100 54.10 2728 2643 48091 11017 96.6 1.300
-04.0 101 54.67 2758 2703 49784 11127 97.0 1.279
-03.0 102 55.24 2789 2763 51537 11233 97.4 1.259
-02.0 103 55.81 2820 2824 53349 11335 97.8 1.239
-01.0 104 56.38 2850 2886 55258 11431 98.1 1.220 ! Near Maximum !
+00.0 105 56.95 2881 2949 57230 11522 98.4 1.201 ! Near Maximum !
+01.0 106 57.52 2912 3012 59281 11609 98.7 1.182 ! Near Maximum !
+02.0 107 58.09 2942 3075 61415 11690 98.9 1.163 ! Near Maximum !
+03.0 108 58.66 2973 3140 63636 11765 99.2 1.145 ! Near Maximum !
+04.0 109 59.23 3003 3205 65948 11835 99.4 1.128 !DANGEROUS LOAD-DO NOT USE!
+05.0 110 59.80 3034 3270 68348 11899 99.5 1.110 !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 105 56.95 3027 3254 70128 11226 100.0 1.106 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 56.95 2682 2555 45739 11130 91.9 1.324
All ran with the same pressure of 65K max. All of them do about the same, with the edge going to the 7mm WSM overall.
Looking at the AI vs the standard 280 nets about 75 FPS, which seems to be about standard, loaded the same.
Sorry to get off track, but there isn't much magic left in ballistics. Faster barrels, tighter chamber's, etc change things a little, but overall, the numbers don't lie too much.
Oh, also, QL shows about 6 grains overall difference between the AI and standard 280, so just about right on with the 10% gain on case capacity. Granted it's all reference, but I think alot of AI's get pushed to higher pressures as they seem to show less signs of excess pressure, so they get pushed harder..
- Thread starter
- #31
Hey Scotty, could you run me the numbers on a 260 and 260 AI with a 26" barrel and a 123 target bullet of your choosing please.
Thanks just wanted to see the difference, or lack of one. I think for now I'm going to just have my 243 chamber recut and set back.
Thanks
Thanks just wanted to see the difference, or lack of one. I think for now I'm going to just have my 243 chamber recut and set back.
Thanks
I don't have a 260 Ackley in my listing Jake. Sorry buddy. Here is the 123 with a 26" tube though.
Cartridge : .260 Rem
Bullet : .264, 123, Nosler CC HPBT 53415
Useable Case Capaci: 47.720 grain H2O = 3.098 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-19
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 42.75 2760 2081 43478 8745 93.7 1.365
-09.0 98 43.23 2791 2128 44966 8850 94.2 1.344
-08.0 99 43.70 2823 2176 46515 8953 94.7 1.323
-07.0 100 44.18 2854 2225 48119 9053 95.2 1.303
-06.0 102 44.65 2886 2274 49782 9149 95.6 1.283
-05.0 103 45.13 2917 2324 51508 9243 96.1 1.264
-04.0 104 45.60 2949 2375 53299 9333 96.5 1.245
-03.0 105 46.08 2980 2426 55159 9420 96.9 1.226
-02.0 106 46.55 3012 2477 57091 9503 97.2 1.207 ! Near Maximum !
-01.0 107 47.03 3043 2529 59098 9583 97.6 1.189 ! Near Maximum !
+00.0 108 47.50 3075 2582 61184 9659 97.9 1.171 ! Near Maximum !
+01.0 109 47.98 3106 2635 63353 9731 98.2 1.154 ! Near Maximum !
+02.0 110 48.45 3138 2688 65608 9799 98.5 1.136 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 48.93 3169 2743 67956 9862 98.7 1.119 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 49.40 3200 2797 70399 9922 99.0 1.103 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 49.88 3232 2852 72945 9977 99.2 1.086 !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 108 47.50 3219 2830 73654 9480 100.0 1.087 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 47.50 2881 2266 49928 9332 91.6 1.280
I used RL19 for it, as QL put it near the top and it should be a good one.
I would bet, equal to equal pressures/guns, you might clear 75FPS more with the AI..
Cartridge : .260 Rem
Bullet : .264, 123, Nosler CC HPBT 53415
Useable Case Capaci: 47.720 grain H2O = 3.098 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-19
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 97 42.75 2760 2081 43478 8745 93.7 1.365
-09.0 98 43.23 2791 2128 44966 8850 94.2 1.344
-08.0 99 43.70 2823 2176 46515 8953 94.7 1.323
-07.0 100 44.18 2854 2225 48119 9053 95.2 1.303
-06.0 102 44.65 2886 2274 49782 9149 95.6 1.283
-05.0 103 45.13 2917 2324 51508 9243 96.1 1.264
-04.0 104 45.60 2949 2375 53299 9333 96.5 1.245
-03.0 105 46.08 2980 2426 55159 9420 96.9 1.226
-02.0 106 46.55 3012 2477 57091 9503 97.2 1.207 ! Near Maximum !
-01.0 107 47.03 3043 2529 59098 9583 97.6 1.189 ! Near Maximum !
+00.0 108 47.50 3075 2582 61184 9659 97.9 1.171 ! Near Maximum !
+01.0 109 47.98 3106 2635 63353 9731 98.2 1.154 ! Near Maximum !
+02.0 110 48.45 3138 2688 65608 9799 98.5 1.136 !DANGEROUS LOAD-DO NOT USE!
+03.0 111 48.93 3169 2743 67956 9862 98.7 1.119 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 49.40 3200 2797 70399 9922 99.0 1.103 !DANGEROUS LOAD-DO NOT USE!
+05.0 113 49.88 3232 2852 72945 9977 99.2 1.086 !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 108 47.50 3219 2830 73654 9480 100.0 1.087 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 47.50 2881 2266 49928 9332 91.6 1.280
I used RL19 for it, as QL put it near the top and it should be a good one.
I would bet, equal to equal pressures/guns, you might clear 75FPS more with the AI..
The 260 AI was quite popular before lapua offered brass. Anymore most people will run a standard 260 at higher pressure close to the AI numbers while taking the feeding problems common with the AI ou out of the equation. I looked at doing a 260 AI until researched the benefits.
gerry
Ammo Smith
- Mar 1, 2007
- 6,996
- 2,043
sask boy":3vrbnwsx said:
The 280 AI would be a good round Dan and worth considering, I do agree that a lot of the extra speed guys get over the standard size cases is from simply loading them to a higher chamber pressure. I also agree that the smaller rounds will gain more speed since there is more shoulder to blow out. Respected author John Barsness has called the 35 Whelen AI one of the most useless AI cartridges to come out since there is so little shoulder to "improve" IIRC he figured that at most you would gain 40 fps at the same pressures. Nosler's 35 Whelen data shows that properly loaded it is a potent round anyway.
If for some strange reason you want to sell off your Rem 700 Win CDL 270 to a certain guy in the west this spring it would find a good home here :wink: :grin:
gerry
Ammo Smith
- Mar 1, 2007
- 6,996
- 2,043
usmc 89":3ccglv3q said:
I like the 260 Rem a lot and the 6.5 Creedmoor does the same thing with a slightly different case design, both are excellent rounds. I have to admit I was very much against the 6.5 Creedmoor when it came out since it isn't much different than the 260, but it is a neat little round with a good design, there is room for both of them.
DrMike
Ballistician
- Nov 8, 2006
- 37,589
- 6,757
gerry":7vkus7ws said:
And I have one of each. Then, again, I tend to have considerable overlap in my arsenal. :roll:
gerry
Ammo Smith
- Mar 1, 2007
- 6,996
- 2,043
Really Mike? :shock:
DrMike
Ballistician
- Nov 8, 2006
- 37,589
- 6,757
gerry":ixv5t73z said:
Nah, not really.
Each has a specific function, if only to make me smile. :mrgreen:The short action 6.5s are all within a few clicks of each other out to the 1k mark, not that it matters because whatever your dope card says to apply that is what your going to do anyway. if your dope and windage assessments are accurate you will hit what your shooting at regardless of what your shooting, however having said that I will have a functioning 6.5-284, 6.5x47, and a 260 short barreled and suppressed in time for the first match in April. how is that for redundant.
DrMike
Ballistician
- Nov 8, 2006
- 37,589
- 6,757
usmc 89":1jl8s7yb said:
It sounds quite normal to me. :grin:
