7 twist 3.50" COL 270 winchester quickload request

[jjmp]

There's another member here that made he's wildcat 270/7 mm Remington magnum ,mybe he will chime in

 

[assasinator]

i ran some numbers and even at 106% case fill you barely make 45000 psi and your right will burn extremely dirty.

thank you. i shot it with 175 TGK and i had pressure signs.

powder speed on a chart is for reference only. as the bullet weight increases a overbore cartridge like the 270 with a extra 4 grains i have, can pop.

that is why i wanted a quickload run. its less conjecture and more empirical.

how about running what i am trying and posting it? please.

 

[assasinator]

Holy smokes you ain't kidding. I just consulted a handy burn rate chart…that's one above H50BMG!!!!!

I agree therefore. Way too slow. Not useless. But expect nowhere near top velocity realized with heavily compressed loads that burn FILTHY! I know this because I've done similar things, H50bmg in a .300 Winnie, h870 in a .270.

And I'm a big believer that the 270 data out there doesn't seem to want to include slower burning powder THAT DO GREAT! Imr 7828 and rl25 have proven to be some awesome powders in my 270, even with a 22 inch pipe. But that bmg burn rate is just waaaay to slow, even for me!

that powder is used for overbore loads in many calibers. i am not really running a 270 win. thanks for the feedback.

 

[assasinator]

i remind that i just shot150gr ablr 62 GRAINS OF MAGPRO WITH 2900 FPS AND LOW PRESSURE. I am adding .5 grains per 5 shots this weekend until i get the max.

that 62 grains was zero compressed load.

 

[assasinator]

Cartridge : .270 Win. (SAAMI)
Bullet : .277, 150, Nosler Accubond LR 58836
Useable Case Capaci: 60.976 grain H2O = 3.959 cm³
Cartridge O.A.L. L6: 3.500 inch = 88.90 mm
Barrel Length : 27.0 inch = 685.8 mm
Powder : Accurate MAGPRO

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 49.60 2272 1720 23222 8524 80.8 1.907
-18.0 85 50.84 2346 1834 25231 8885 82.9 1.834
-16.0 87 52.08 2421 1952 27404 9235 84.8 1.764
-14.0 89 53.32 2495 2073 29756 9574 86.7 1.697
-12.0 91 54.56 2570 2199 32303 9900 88.4 1.633
-10.0 93 55.80 2644 2328 35062 10210 90.0 1.573
-08.0 95 57.04 2718 2461 38057 10504 91.5 1.515
-06.0 98 58.28 2793 2598 41309 10781 92.9 1.460
-04.0 100 59.52 2867 2737 44843 11037 94.2 1.407
-02.0 102 60.76 2941 2881 48694 11273 95.4 1.356
+00.0 104 62.00 3015 3027 52893 11486 96.4 1.308
+02.0 106 63.24 3088 3176 57479 11676 97.3 1.261 ! Near Maximum !
+04.0 108 64.48 3161 3329 62466 11840 98.1 1.217 ! Near Maximum !
+06.0 110 65.72 3234 3484 67897 11978 98.7 1.174 !DANGEROUS LOAD-DO NOT USE!
+08.0 112 66.96 3307 3642 73824 12089 99.2 1.133 !DANGEROUS LOAD-DO NOT USE!
+10.0 114 68.20 3379 3803 80305 12170 99.6 1.094 !DANGEROUS LOAD-DO NOT USE!

these closely match what i saw at the range.


i also ran the numbers in a variety of ways. ordered retumbo. only wasted 45.00. i'll use it for other things.

 

[assasinator]

so this is the last post in this thread....there will be a new one next weekend....

i loaded the 270 long fast with 170gr nosler tipped. they just will never reach my goals. i mean if i could never do anything with my barrel, i would deal with it and take months to maximize accuracy for the velocity that i can get.

2800 fps is decent for a 170 in 270 win. i was hoping that with the lower pressures and higher capacity from my chamber, i could push it farther. i used magpro.

i havent tried magnum primers, but i doubt it would matter. so....

i am getting it rechambered to 270 weatherby mag tuesday. i dont waste powder, bullets, and time. at least i try not to.

the freebore will remain the same (shortened by .090") so it will perform like my other belted mags. at least i gave it the old college TRY lol.

i dont have any weatherby mags. i generally get specific chambers cut that meet my requirements. i am only getting the 270 weatherby cut because the gunsmith has it in his toolbox. I REALLY wanted 270-338 winmag with a .040 longer neck. my 338 based loadings dont split belts off like weatherbys do.

oh well. i will have to neck size the 270 bee and trim it. i just happen to have 75 270 weatherby brass because i always planned for this.

i also have 257 BEE cases i made 270-338 cases for fireforming. its hard to knock back the 270 BEE shoulder. anyway. later.

the retumbo and 24n41 may work for this. we'll see. 175 grain TGK.

 

[assasinator]

didnt want to start a new thread.

hornady has h1000 in stock.

just ordered 4 lbs. i mean the 60 pounds of different powders i have now isnt enough lol. i believe it will work great with the 270 weatherby with 3.50" COAL.