POP, .280 Remington / H1000 / 140-Grain Accubonds?

[JD338]

Pop,

Good read on the 280 Remington, thanks for posting the G2.

JD338

 

[RiverRider]

I like Jim Carmichael, but he's wrong. The Remington 740 self-loader, which was Remington's launching pad for the .280, was also chambered in .244 Remington (65,000 psi) and the .308 Winchester (62,000 psi). The 760 pump-action had been chambered for .270 Winchester (65,000 psi) in 1953, years before the same rifle was produced in the .280 chambering.

Neither the 740 nor the 760 required chamber pressures to be limited to 50,000 cup (or 60,000 psi), else they'd not have been produced in .244, .270, or .308. Why these myths and legends continue to be propagated is beyond me.

 

[RiverRider]

Whoa, whoa, whoa! I just saw the part where Carmichael says the 740 was NOT chambered in .270 Winchester. That is interesting...Remington thinks it was. But there is still the issue of the .244 (or 6mm Remington), whatever the truth may be. What? Whoa, whoa! He mentions the .244 again also.

I had not seen this info before and believed it to be more repetition of the conventional nonsense. I guess it is not. I will go back and read it more carefully---after I have already pronounced Carmichael to be wrong, of course. But hey, that sort of thing happens!


edit: I was looking at the wrong stuff---Remington does not list the 740 as having been offered in .270 Win. It was the Model 760 that was offered in .270 Win.

By George, that Carmichael fellow is pretty sharp. :wink:

 

[FOTIS]

POP, I wish you had run the same powders for that comparison of .30-06 to .270. In fact, it might be instructive to run .270, .280, and .30-06 with 150-grain bullets and the same powder, like maybe RL22 or H1000.

I can but it would be counter productive. No one powder would demonstrate each cartridge's full potential with 150 gr bullets, but if you insist.


AGAIN I RAN THESE AT 65K PSI....NOT A GOOD IDEA...FOR COMPARISON ONLY!!!


Cartridge : .280 Rem.
Bullet : .284, 150, Nosler BalTip 39586
Cartridge O.A.L. L6: 3.330 inch or 84.58 mm
Barrel Length : 22.0 inch or 558.8 mm
Powder : Alliant Reloder-22

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 91 50.40 2458 2012 35261 10879 89.4 1.389
-18.0 94 51.66 2526 2124 37938 11247 90.9 1.346
-16.0 96 52.92 2594 2241 40836 11601 92.3 1.299
-14.0 98 54.18 2663 2362 43974 11939 93.6 1.254
-12.0 100 55.44 2732 2486 47380 12258 94.8 1.210
-10.0 103 56.70 2801 2614 51078 12556 95.8 1.169
-08.0 105 57.96 2871 2745 55103 12832 96.8 1.128
-06.0 107 59.22 2941 2880 59486 13083 97.6 1.089 ! Near Maximum !
-04.0 110 60.48 3010 3018 64272 13308 98.3 1.052 ! Near Maximum !
-02.0 112 61.74 3080 3160 69505 13503 98.9 1.016 !DANGEROUS LOAD-DO NOT USE!
+00.0 114 63.00 3150 3305 75218 13669 99.4 0.981 !DANGEROUS LOAD-DO NOT USE!
+02.0 116 64.26 3220 3453 81448 13801 99.7 0.947 !DANGEROUS LOAD-DO NOT USE!
+04.0 119 65.52 3289 3604 88278 13899 99.9 0.915 !DANGEROUS LOAD-DO NOT USE!
+06.0 121 66.78 3359 3758 95786 13960 100.0 0.883 !DANGEROUS LOAD-DO NOT USE!
+08.0 123 68.04 3428 3915 104063 14001 100.0 0.853 !DANGEROUS LOAD-DO NOT USE!
+10.0 126 69.30 3498 4074 113220 14032 100.0 0.824 !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 114 63.00 3294 3613 92058 13150 100.0 0.905 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 114 63.00 2945 2888 59674 13465 94.2 1.082 ! Near Maximum !


Cartridge : .270 Win. (SAAMI)
Bullet : .277, 150, Nosler BalTip 27150
Cartridge O.A.L. L6: 3.340 inch or 84.84 mm
Barrel Length : 22.0 inch or 558.8 mm
Powder : Alliant Reloder-22

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 48.00 2395 1911 34180 11028 90.2 1.444
-18.0 90 49.20 2460 2015 36692 11394 91.6 1.403
-16.0 92 50.40 2525 2123 39399 11747 92.9 1.356
-14.0 94 51.60 2590 2234 42317 12085 94.2 1.311
-12.0 96 52.80 2655 2348 45471 12404 95.3 1.267
-10.0 99 54.00 2721 2465 48879 12704 96.3 1.225
-08.0 101 55.20 2786 2586 52567 12982 97.1 1.184
-06.0 103 56.40 2852 2709 56562 13237 97.9 1.145 ! Near Maximum !
-04.0 105 57.60 2917 2835 60888 13467 98.6 1.107 ! Near Maximum !
-02.0 107 58.80 2983 2964 65541 13670 99.1 1.070 !DANGEROUS LOAD-DO NOT USE!
+00.0 110 60.00 3048 3095 70578 13845 99.5 1.035 !DANGEROUS LOAD-DO NOT USE!
+02.0 112 61.20 3114 3229 76042 13988 99.8 1.001 !DANGEROUS LOAD-DO NOT USE!
+04.0 114 62.40 3179 3365 81979 14100 100.0 0.969 !DANGEROUS LOAD-DO NOT USE!
+06.0 116 63.60 3243 3504 88443 14180 100.0 0.937 !DANGEROUS LOAD-DO NOT USE!
+08.0 118 64.80 3308 3644 95496 14245 100.0 0.907 !DANGEROUS LOAD-DO NOT USE!
+10.0 120 66.00 3372 3787 103211 14303 100.0 0.877 !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 60.00 3185 3379 85932 13330 100.0 0.955 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 110 60.00 2852 2710 56064 13657 94.6 1.141 ! Near Maximum !




Not optimum powder for the 30-06 and the 150 BT.


Cartridge : .30-06 Spring.
Cartridge : .30-06 Spring.
Bullet : .308, 150, Nosler BalTip 30150
Cartridge O.A.L. L6: 3.340 inch or 84.84 mm
Barrel Length : 22.0 inch or 558.8 mm
Powder : Alliant Reloder-22

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 90 50.40 2221 1643 25371 7833 75.4 1.473
-18.0 92 51.66 2284 1738 27155 8174 77.3 1.433
-16.0 94 52.92 2348 1836 29074 8513 79.1 1.393
-14.0 96 54.18 2413 1940 31150 8850 80.8 1.355
-12.0 99 55.44 2479 2047 33393 9182 82.5 1.317
-10.0 101 56.70 2546 2159 35818 9508 84.2 1.279
-08.0 103 57.96 2614 2276 38444 9827 85.8 1.239
-06.0 105 59.22 2683 2397 41294 10137 87.4 1.198
-04.0 108 60.48 2752 2522 44373 10437 88.9 1.158
-02.0 110 61.74 2822 2653 47753 10723 90.3 1.119
+00.0 112 63.00 2893 2788 51433 10995 91.7 1.081
+02.0 114 64.26 2965 2927 55447 11252 92.9 1.044 ! Near Maximum !
+04.0 117 65.52 3037 3072 59845 11489 94.1 1.009 ! Near Maximum !
+06.0 119 66.78 3110 3221 64675 11708 95.2 0.975 !Near Maximum !!
+08.0 121 68.04 3183 3374 69992 11904 96.2 0.941 !DANGEROUS LOAD-DO NOT USE!
+10.0 123 69.30 3257 3533 75864 12076 97.1 0.909 !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 112 63.00 3092 3183 63008 11372 97.9 0.989 ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:
-Ba 112 63.00 2649 2337 41551 9995 81.3 1.197

 

[RiverRider]

Thanks, POP. The results of that little experiment are revealing. I didn't expect the .30-06 to require so much of the powder to get up to the 65kpsi mark! The .270/.280 result is about what I expected, though.

That software is really great!

 

[FOTIS]

Anytime

 

[RiverRider]

Update:


I chronographed my H1000 loads this last weekend, taking care to shade the sensor slots. My load is 140-grain Accubonds over a higher-than-book charge of H1000 and I won't specify what the charge is, but think .270 Winchester.

I fired 10 rounds. Average velocity was 2887 fps, the extreme spread was about 12 fps, and SD was 4.6 fps.

H1000 is NOT too slow for .280, nor is RL22 or any number of the slower powders often passed over.

I am having accuracy issues with the rifle (can't get consistent sub-MOA performance), but that has been an ongoing thing with any powder I have tried and I attribute it to my insistence on free-floating the barrel. I am now ready to throw in the towel and put in a pressure point. If that results in undesirable POI shifts in the future, I'll get rid of the rifle and try again. I suspect that if I can get this rifle to perform, I'll get consistent sub-MOA groups using H1000. I have never had more consistent velocities in any rifle using any powder!

 

[RiverRider]

I ended up dumping the rifle that gave me so much trouble (a 77 Mk.II) and replaced it with an economy-grade custom based on a VZ24 action.

This rifle gave indications of wanting to shoot from day one, but I was stuck on the idea of using 140-grain Accubonds. I wanted to make use of the magazine, so my OAL was somewhat limited and I could not seat an AccuBond any closer to the lands than about .050 inch. Trial after trial ended in disappointment, so I decided to see if some 150-grain Partitions would shoot. BINGO. Using H1000 to drive them, I got MOA groups immediately. Should I ever get to go on an elk hunt, I have the combination!

Partitions ain't cheap, and I wanted to have a bullet for kicking around and light game, so I tried some Winchester 150-grain Power Points, also pushed by H1000. First day out with five trial loads complete with an arbitrarily picked seating depth yielded five very good groups, one of which measured .34 inch.

I forgot my tripod the day I shot the Partitions so I could not chronograph the loads. I did remember everything the day I shot the Power Points. Velocity consistency was very good throughout the charge range, and a .34-inch group with the 61.0-grain charge speaks for itself. I was able to reach 2900 fps using 62.0 grains, but accuracy was not as good. Three of the loads produced MOA groups and the other two spanned just a bit over MOA. I call that very good performance.

I think H1000 works just fine in the .280!

 

[FOTIS]

Good deal!!!!

 

[jwp475]

The problem I see when using these slower powders is getting enough of it into the case. During the days I played with RL22, I came to the conclusion that I probably could not get enough of it under a 139- or 140-grain bullet to cause an over-pressure situation without trying real hard (this may or may not be strictly true).

Now, maybe there is some subtlety relating to chamber pressures I have missed all these years...but, is 65,000 psi safe in a modern bolt-action chambered in .270 Winchester? SAAMI seems to think so, or that would not be the spec. Let's see...yup, my double-check confirms it.

I realize that SAAMI specs the .280 at 60,000 psi, but I need a logical explanation as to why a .270 case would only be able to withstand 60,000 psi when necked up to .284." I do not think there IS a logical explanation. What I am saying is that I think it is perfectly safe to load the .280 up to 65,000 psi. Because someone arbitrarily decided to write "60,000 psi" next to ".280 Remington" doesn't mean a whole lot to me.

The Remington 742 semi auto would not handle the pressure of the 270 so Remington designed the 280 to give near 270 ballistics in the 742, thus the lower pressure