270wby

T

theddguide

Beginner
Jun 16, 2018
72
0
Can anyone run some numbers please for a 270wby slingin 140 accubonds with 7828ssc?

The new nosler book says 71 max and two other sources say 73.5. Was gonna work up from 70 to 73.5. Also, what's a max velocity I should look for? How should I go about seating depth on a weatherby? Never loaded for one. Any tips would be appreciated.

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Nothing like what you're looking for, I suspect. However, it does project a near identical velocity. I'd be prone to test the propellant using care and watching for pressure signs. IMR7828 SSC will work, and work well. The charge is dependent on the one loading.

Code: 
Cartridge          : .270 Weath. Mag.
Bullet             : .277, 140, Nosler AccuBond 54765
Useable Case Capaci: 73.581 grain H2O = 4.778 cm³
Cartridge O.A.L. L6: 3.295 inch = 83.69 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : IMR 7828 SSC

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   88    61.38   2936    2679   44188  11811     96.2    1.382
-09.0   89    62.06   2970    2741   45704  11942     96.6    1.360
-08.0   90    62.74   3003    2804   47276  12067     97.1    1.339
-07.0   91    63.42   3037    2868   48907  12188     97.5    1.318
-06.0   92    64.10   3071    2932   50592  12302     97.8    1.297
-05.0   93    64.79   3105    2996   52345  12411     98.2    1.277
-04.0   94    65.47   3138    3062   54163  12514     98.5    1.257
-03.0   95    66.15   3172    3128   56047  12611     98.8    1.238  ! Near Maximum !
-02.0   96    66.83   3205    3194   58003  12701     99.0    1.219  ! Near Maximum !
-01.0   97    67.51   3239    3261   60032  12785     99.3    1.200  ! Near Maximum !
+00.0   98    68.20   3272    3329   62137  12863     99.5    1.182  ! Near Maximum !
+01.0   99    68.88   3305    3397   64324  12934     99.6    1.163  !DANGEROUS LOAD-DO NOT USE!
+02.0  100    69.56   3339    3465   66598  12998     99.8    1.146  !DANGEROUS LOAD-DO NOT USE!
+03.0  101    70.24   3372    3534   68959  13055     99.9    1.128  !DANGEROUS LOAD-DO NOT USE!
+04.0  102    70.92   3405    3603   71412  13105     99.9    1.111  !DANGEROUS LOAD-DO NOT USE!
+05.0  103    71.61   3437    3673   73968  13147    100.0    1.094  !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     98    68.20   3419    3634   75449  12381    100.0    1.091  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba     98    68.20   3063    2916   50142  12665     94.4    1.299
 
Finally got a load worked up I think. Aside from a couple jerks of the trigger these are excellent groups for me. I think I've settled on 72g imr 7828ssc with a 140 AccuBond at 3250. My coal is 3.30, would you tinker with that at all given that I know my outside shots were not perfect trigger pulls? First pic was 71.5g and about 20-25fps slower. 6 shots each. Let me know what y'all think.
2e32df616c7762896222d6d4fc5b9080.jpg
c7db6df085523c0ea8f6ab5de33748c6.jpg


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Well, the grouping certainly shows promise. It'll do for about any game you might wish to hunt. All you need do is adjust your scope to permit a 200-250 yard zero, and you're good to go.
 
DrMike":37zcm8h0 said:
Well, the grouping certainly shows promise. It'll do for about any game you might wish to hunt. All you need do is adjust your scope to permit a 200-250 yard zero, and you're good to go.
Click to expand...
I moved it up for a 100yd zero as of now. Haven't decided if I want that or 200 for my dial from leupold

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DrMike":1ktuiftt said:
Well, the grouping certainly shows promise. It'll do for about any game you might wish to hunt. All you need do is adjust your scope to permit a 200-250 yard zero, and you're good to go.
Click to expand...
What was the saying that went something like,,, rifle shooting side to side , and rifles shooting up and down..

I cannot for the life of me remember that..

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When a rifle shoots groups that are three times as wide, as they are tall…. I take a serious look at the bedding.
 
Songdog":1bi6kgq5 said:
When a rifle shoots groups that are three times as wide, as they are tall…. I take a serious look at the bedding.
Click to expand...
If I was capable of making a perfect shot while holding the crosshairs perfectly in the middle of the bullseye every shot, I could see your point. But, I'm just an average guy who, although, shoots more than the average hunter, is far from being an expert. I just do the best I can and as stated, I know I didn't execute perfect shots, therefore, I'm confident the gun is at least 2x more accurate than I portray it to be. Also, being a factory weatherby rifle, I'm going to assume they did what they do on all these models as far as bedding.

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Never “assume” when it comes to factory “bedding”.

A scoped rimfire, and a brick of ammo, will go a looooong way toward better shooting.

I once heard a grumpy Alaskan troll say: “spent primers are the ultimate tutorial”.
 
I don't know, how far do you plan on shooting? That bottom group looks like 5 shots under an inch. If so you're not that far off. If you don't plan on shooting over 300 yds, you're not off at all. The rifle will hit anything you want, where you want, to 300 and probably farther You'd be better off spending time practicing in whatever field positions you're most likely to use.

If you want or need better maybe try seating a little deeper if you're somewhat close to the lands.....some .020-.025 deeper, some .045-.050deeper, see if it gets tighter or goes the other way.
 
If that’s about what you’re capable of I’d be fine taking it hunting. If it holds up at longer range I’d say you have a good combo.
 
A lot of well built Weatherby rifles shot factory loaded ammo very accurately. My custom 270wby shoots factory Weatherby 140AB ammo better than 0.2 MOA...
 
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