Retumbo in .300 Win. Mag?

.300winmag

Handloader
Oct 17, 2011
660
2
Anyone tried this? I've got two#'s of it and want to give it a shot with 215 Hybrids. If I remember correctly, DrMike got good results with it and a 210 VLD. Anyone else given it a shot?
 
I did load development for a gentleman using Retumbo and 210 grain VLDs. This load gave good velocities and excellent accuracy.

With the 215 VLD, it would be a compressed load, though not excessively compressed.

Cartridge : .300 Win. Mag.(W)
Bullet : .308, 215, Berger Hybrid G7 #30423
Useable Case Capaci: 78.664 grain H2O = 5.108 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon Retumbo

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 89 64.72 2269 2457 30031 10892 94.9 1.709
-18.0 91 66.34 2332 2595 32187 11227 96.2 1.663
-16.0 93 67.96 2395 2738 34522 11533 97.3 1.618
-14.0 95 69.57 2458 2885 37035 11809 98.3 1.574
-12.0 98 71.19 2521 3035 39749 12052 99.0 1.518
-10.0 100 72.81 2584 3189 42682 12258 99.5 1.467
-08.0 102 74.43 2647 3345 45856 12427 99.9 1.418
-06.0 104 76.05 2709 3504 49296 12555 100.0 1.370
-04.0 107 77.66 2771 3665 53027 12656 100.0 1.324 ! Near Maximum !
-02.0 109 79.28 2832 3829 57083 12751 100.0 1.280 ! Near Maximum !
+00.0 111 80.90 2892 3994 61498 12841 100.0 1.237 ! Near Maximum !
+02.0 113 82.52 2953 4162 66314 12926 100.0 1.196 !DANGEROUS LOAD-DO NOT USE!
+04.0 115 84.14 3012 4332 71576 13005 100.0 1.156 !DANGEROUS LOAD-DO NOT USE!
+06.0 118 85.75 3072 4505 77337 13078 100.0 1.118 !DANGEROUS LOAD-DO NOT USE!
+08.0 120 87.37 3131 4681 83661 13144 100.0 1.080 !DANGEROUS LOAD-DO NOT USE!
+10.0 122 88.99 3191 4860 90622 13204 100.0 1.045 !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 111 80.90 3015 4339 76991 12293 100.0 1.135 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 111 80.90 2701 3483 48742 13352 98.4 1.371

I'd be inclined to give it a go if I were testing.
 
Thank's DrMike! It does appear to produce significantly more velocity than H-1000. I was worried about unburnt powder messing with ES and SD with Retumbo; but, that does not seem to be an issue. I think I will pursue this avenue.

How do the #'s look with these parameters?

.300 Win. Mag.
215 Berger Hybrid.
Retumbo
28" barrel
OAL 3.680"
Case volume: 92.22grs H2O filled to top of case mouth.

Another thought, if you wouldn't mind could you run the numbers above for both the 215 and 230 grain Bergers?

I've got about 100 of each left and am curios. I'd appreciate it if you wouldn't mind.
 
Note that these assume Winchester Western cases. QL allows for the differences in case volume using Federal, Norma and Remington cases.

Cartridge : .300 Win. Mag.(W)
Bullet : .308, 215, Berger Hybrid G7 #30423
Useable Case Capaci: 83.484 grain H2O = 5.421 cm³
Cartridge O.A.L. L6: 3.680 inch = 93.47 mm
Barrel Length : 28.0 inch = 711.2 mm
Powder : Hodgdon Retumbo

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 87 67.20 2400 2750 30251 9788 97.4 1.845
-18.0 89 68.88 2463 2896 32408 10029 98.3 1.796
-16.0 91 70.56 2526 3046 34732 10243 99.1 1.748
-14.0 93 72.24 2588 3198 37234 10427 99.6 1.699
-12.0 96 73.92 2650 3353 39932 10578 99.9 1.644
-10.0 98 75.60 2712 3511 42842 10697 100.0 1.590
-08.0 100 77.28 2772 3670 45985 10794 100.0 1.538
-06.0 102 78.96 2832 3830 49383 10888 100.0 1.488
-04.0 104 80.64 2892 3992 53062 10978 100.0 1.441 ! Near Maximum !
-02.0 106 82.32 2951 4156 57050 11064 100.0 1.394 ! Near Maximum !
+00.0 109 84.00 3009 4322 61379 11145 100.0 1.350 ! Near Maximum !
+02.0 111 85.68 3067 4490 66087 11223 100.0 1.307 !DANGEROUS LOAD-DO NOT USE!
+04.0 113 87.36 3124 4660 71215 11295 100.0 1.266 !DANGEROUS LOAD-DO NOT USE!
+06.0 115 89.04 3182 4833 76812 11363 100.0 1.226 !DANGEROUS LOAD-DO NOT USE!
+08.0 117 90.72 3239 5008 82931 11426 100.0 1.188 !DANGEROUS LOAD-DO NOT USE!
+10.0 119 92.40 3296 5186 89637 11483 100.0 1.151 !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 109 84.00 3121 4650 76856 10696 100.0 1.243 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 109 84.00 2833 3833 48538 11751 99.6 1.492

If you measure maximum case capacity, overflow by forming a convex meniscus, it will give you a truer measure of capacity and velocity.
 
Thank you!

I did not know QL had the option for different brass manufactures. I use R&P brass. I measured case volume as you described. Allowing an overflow or water so the surface tension of the water allowed a dome meniscus slightly above the case mouth. I hated chemistry in college but that is one thing that I did find useful and retained from those dreaded chem labs.
 
.300winmag":78mzg3ko said:
Thank you!

I did not know QL had the option for different brass manufactures. I use R&P brass. I measured case volume as you described. Allowing an overflow or water so the surface tension of the water allowed a dome meniscus slightly above the case mouth. I hated chemistry in college but that is one thing that I did find useful and retained from those dreaded chem labs.

QL does not provide data for differing case manufacturers, except in a couple of selected instances--300 Win May is one of those instances.

Cartridge : .300 Win. Mag.(W)
Bullet : .308, 215, Berger Hybrid G7 #30423
Useable Case Capaci: 85.082 grain H2O = 5.524 cm³
Cartridge O.A.L. L6: 3.680 inch = 93.47 mm
Barrel Length : 28.0 inch = 711.2 mm
Powder : Hodgdon Retumbo

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 86 68.00 2409 2771 30316 9905 97.6 1.847
-18.0 88 69.70 2472 2917 32474 10145 98.5 1.798
-16.0 91 71.40 2535 3067 34796 10357 99.2 1.750
-14.0 93 73.10 2597 3220 37292 10538 99.7 1.701
-12.0 95 74.80 2659 3375 39985 10687 99.9 1.646
-10.0 97 76.50 2720 3532 42889 10803 100.0 1.592
-08.0 99 78.20 2780 3690 46023 10904 100.0 1.541
-06.0 101 79.90 2840 3850 49408 11000 100.0 1.491
-04.0 103 81.60 2899 4012 53072 11094 100.0 1.444 ! Near Maximum !
-02.0 106 83.30 2957 4176 57040 11183 100.0 1.398 ! Near Maximum !
+00.0 108 85.00 3015 4341 61344 11268 100.0 1.353 ! Near Maximum !
+02.0 110 86.70 3073 4508 66019 11348 100.0 1.311 !DANGEROUS LOAD-DO NOT USE!
+04.0 112 88.40 3130 4678 71106 11424 100.0 1.270 !DANGEROUS LOAD-DO NOT USE!
+06.0 114 90.10 3187 4850 76653 11496 100.0 1.230 !DANGEROUS LOAD-DO NOT USE!
+08.0 116 91.80 3244 5025 82711 11562 100.0 1.192 !DANGEROUS LOAD-DO NOT USE!
+10.0 119 93.50 3301 5202 89342 11622 100.0 1.155 !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 85.00 3127 4667 76777 10822 100.0 1.247 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 108 85.00 2842 3855 48473 11879 99.7 1.495
 
Either way, that looks pretty fearsome with that big 215 buddy!


I am still waiting for you to run those 210 ABLRs in that rifle though.. This is Nosler man.. We wanna see what those sewing needles do out of a 1st class rifle! :grin:
 
i have with the 210 gr. matrix. got mixed results and feelings. went back to 180 gr. bullets. will have to look in the log book for the recipes.
 
SJB358":34048xn7 said:
Either way, that looks pretty fearsome with that big 215 buddy!


I am still waiting for you to run those 210 ABLRs in that rifle though.. This is Nosler man.. We wanna see what those sewing needles do out of a 1st class rifle! :grin:

Man if I could find some I would love to try them! BL posted his findings and it had a BC of .651 I believe...Beats a 210 Berger by a bit, and I loved that bullet! Would love to shoot NOSLERS!!! I've shot a load of game with accubonds and BT's and they always make me smile, whether on paper or meat :mrgreen:
 
Got ya. I will keep my ear to the ground and keep a look out for you. Love to see a guy like you or your family smash some deer and elk with that 300.
 
Thanks! I've got a few giftcards to cabela's I've been saving to use, but the local one never has them, and last I looked online, they were out. Would love to smash a cow this year with one. Was able to get a leftover tag, so I actually get to hunt for myself! :mrgreen:

I also think I have my Dad talked into using the 129 LRAB on his buck this year with the 6.5x47; rifle should be done end about two months before his hunt. If you spot any of the 210's or 129's give me a shout!
 
.300winmag":30zcn7zj said:
Thanks! I've got a few giftcards to cabela's I've been saving to use, but the local one never has them, and last I looked online, they were out. Would love to smash a cow this year with one. Was able to get a leftover tag, so I actually get to hunt for myself! :mrgreen:

I also think I have my Dad talked into using the 129 LRAB on his buck this year with the 6.5x47; rifle should be done end about two months before his hunt. If you spot any of the 210's or 129's give me a shout!

Will do. Love to see the Lapua go to work.
 
I would not give give up on Retumbo with the heavy bullets and I would also be trying RL25 as when I get around to load work up they will be used behind some 190 ABLR and Nosler told me that in July they would be running some 210's but still waiting! I think the 210's would run well outta my 300 Weatherby with a warm load of RL25 :mrgreen: I am feeling 190's outta my 300 Win Mag will be doing tiny groups with the components I have for it! The heavy for caliber bullets only need the proper twist barrel combos to stabilize them along with proper velocity!

http://www.dtic.mil/get-tr-doc/pdf?AD=ADA554683
Bryan Litz did some testing explaining his testing of the ABLR's ! Most work fine but he found small errors in some BC's and he tested them all ! Pretty good read! Below!

http://www.longrangehunting.com/forums/ ... ts-137554/
 
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