257 Bee Data ?

[Powerstroke]

Ok - I just picked up the new Berger loadinng manual, and have questions. I understand there will always be slight discrepancies from one mfg to another, but this one seems excessively wide.
I'm looking at the 115 VLD's
Berger coal = 3.170 stated
Nosler #6 = 3.250 stated. ( yes I'll have #7 as soon as I see it )

Powder 7828ssc
Berger max 64.6
Nosler max 69.0
I understand these are two different bullets. VLD's vs BTips. Is there still enough difference between
The two to equate to 4.4gr difference?
I used 68.0 grains without any pressure signs

Powder RL25
Berger max 66.9
Nosler max 72.0

Again why that large of difference? I have a good load w/ 70.0 gr & 115 BTips - would like
To play with the same charge with the VLD's but now questioning it.

Any thoughts? Thanks!

 

[gerry]

Soft cup are core Berger's develop a lot more pressure? That would be my guess.

 

[Powerstroke]

I might say possibly, however when I look at other cartridges in my safe and compare them, they are much closer, .270wsm, 7-08, .280 between the two manuals.

 

[DrMike]

Some figures generated by QL:

Cartridge : .257 Weath. Mag
Bullet : .257, 115, Nosler BalTip 25115
Useable Case Capaci: 76.471 grain H2O = 4.965 cm³
Cartridge O.A.L. L6: 3.170 inch = 80.52 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : IMR 7828

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 78 53.20 2642 1783 31872 12393 90.4 1.542
-18.0 80 54.53 2710 1875 34034 12807 91.8 1.505
-16.0 82 55.86 2777 1970 36340 13207 93.1 1.469
-14.0 83 57.19 2845 2067 38804 13590 94.3 1.424
-12.0 85 58.52 2913 2167 41432 13954 95.4 1.380
-10.0 87 59.85 2981 2269 44244 14298 96.4 1.337
-08.0 89 61.18 3049 2374 47247 14618 97.3 1.296
-06.0 91 62.51 3117 2480 50460 14914 98.0 1.257
-04.0 93 63.84 3184 2589 53876 15184 98.7 1.219
-02.0 95 65.17 3251 2699 57494 15425 99.2 1.183 ! Near Maximum !
+00.0 97 66.50 3317 2810 61348 15637 99.6 1.147 ! Near Maximum !
+02.0 99 67.83 3384 2923 65455 15817 99.8 1.114 !DANGEROUS LOAD-DO NOT USE!
+04.0 101 69.16 3449 3038 69836 15965 100.0 1.081 !DANGEROUS LOAD-DO NOT USE!
+06.0 103 70.49 3514 3153 74513 16081 100.0 1.050 !DANGEROUS LOAD-DO NOT USE!
+08.0 105 71.82 3578 3270 79507 16187 100.0 1.019 !DANGEROUS LOAD-DO NOT USE!
+10.0 107 73.15 3642 3387 84848 16289 100.0 0.990 !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 97 66.50 3466 3068 73552 15128 100.0 1.059 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 97 66.50 3107 2465 49485 15358 94.7 1.263

Cartridge : .257 Weath. Mag
Bullet : .257, 115, Berger VLD G7 #25513
Useable Case Capaci: 76.703 grain H2O = 4.980 cm³
Cartridge O.A.L. L6: 3.170 inch = 80.52 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : IMR 7828

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 78 53.60 2658 1804 32360 12512 90.7 1.534
-18.0 80 54.94 2726 1898 34566 12926 92.1 1.497
-16.0 82 56.28 2794 1994 36922 13325 93.4 1.461
-14.0 84 57.62 2863 2093 39438 13706 94.6 1.414
-12.0 86 58.96 2931 2194 42125 14068 95.7 1.370
-10.0 88 60.30 2999 2297 44997 14408 96.6 1.327
-08.0 90 61.64 3067 2402 48071 14724 97.5 1.287
-06.0 92 62.98 3135 2510 51356 15015 98.2 1.247
-04.0 94 64.32 3203 2619 54837 15279 98.8 1.210 ! Near Maximum !
-02.0 96 65.66 3270 2730 58533 15514 99.3 1.173 ! Near Maximum !
+00.0 98 67.00 3337 2843 62473 15718 99.7 1.138 ! Near Maximum !
+02.0 99 68.34 3403 2957 66674 15890 99.9 1.105 !DANGEROUS LOAD-DO NOT USE!
+04.0 101 69.68 3469 3072 71156 16029 100.0 1.072 !DANGEROUS LOAD-DO NOT USE!
+06.0 103 71.02 3534 3189 75943 16141 100.0 1.041 !DANGEROUS LOAD-DO NOT USE!
+08.0 105 72.36 3598 3306 81059 16247 100.0 1.011 !DANGEROUS LOAD-DO NOT USE!
+10.0 107 73.70 3662 3424 86531 16348 100.0 0.982 !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 67.00 3484 3099 74860 15191 100.0 1.051 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 98 67.00 3127 2497 50392 15485 95.0 1.253

Nosler No. 7 still shows 69 grains maximum load.

I'll suggest different lots of powder and different test calibration. Your chamber is whatever your chamber is, so you may indeed be able to safely use a somewhat higher charge. I haven't fully worked through the Berger manual. I do know that prior to publication of this manual, Berger was using QL with the recommendation that the loads be worked up safely. There may well have been an anomaly in their testing sequence or in the data generated, or it is just possible that there is an error in publication. Hornady and Barnes are notorious for publishing corrections after their manuals are released; perhaps Berger will fall into the same category.

 

[Guy Miner]

I had to reduce my .25-06 loads when I swapped from Berger VLD's to Nosler Ballistic Tips, all 115 grains.

Dropped the charge by 2.5 grains, and all was well. Prior to that I got signs of high pressure.

FWIW, Guy

 

[Kodiak]

The .257Bee is a pretty dang'd good cartridge. Flat-shooting, low recoil, med.wt. rifles, usually.

My Vanguard loves the 100 BTs and 110ABs, loaded to close to posted manual MAX. loads.

I have not tried any of the longer, sleek-looking, high b.c. bullets, but I an interested in your findings.

The OAL in most Weatherby throats don't get the bullet very close to touching, but thats the secret!. You may have to let them "jump" a little to get desired groups.

Keep us posted,

Old Jim

 

[Powerstroke]

Thanks to all -
I went ahead and ran with the 70grains I've been shooting for the B-tips and didn't have any pressure signs. It was too windy to set the chrony up, so I don't have a decent comparison. We'll wait another day for better conditions and see how the groups go - it's going to take a bit to beat the B-tips.

I did fire a couple into some gallon milk jugs @ 155 yards - The 115 VLD didn't make it out of the second jug - only a piece of the jacket remained.