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Joined: Nov 2005
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OP
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Joined: Nov 2005
Posts: 1,943 |
After initially shooting well my new 308 Win. Rem 700 was stringing shots vertically. After trying a few different things, I just re-bedded it and am getting nice results with the 150 TTSX and E-tip.. It really is amazing the difference a proper bedding job can do. To my main question...what have you experienced in terms of max loads with E-tips? I called Nosler and the tech said they always recommend backing off two grains from any max listed in their 5th Edition loading manual. What makes me a little nervous is their max load of Varget is listed at 48.5 grains; this is about 1.5 grains higher than any other source I can locate. I have avoided the E-tip in the past due to supposed higher pressures, but it is accurate, has a high BC, and supposedly expands wider than the Barnes. At 45.5g Varget I got an average of 2745 fps with the E-tip. With the TTSX I have got about 2740 fps with 46.6g Varget and 45.5 grains RL15. Neither of these loads are book max, but close with the RL 15. I�m thinking same/same velocity means I am close to max with the E-tip and 45.5g Varget (21.5 inch barrel btw). What are your thoughts? Before... After re-bedding....
The truth angers those whom it does not convince
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Joined: Oct 2004
Posts: 4,340
Campfire Tracker
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Campfire Tracker
Joined: Oct 2004
Posts: 4,340 |
fwiw in my 30-06 the 150 e tip did about 60 fps faster than cup and core bullets with the same load. Here is a quickload projection. My version doesn't have the etip so I used the older (longer) barnes xbt as a "like" bullet. If this data is usable and I think it is you are near max based on speed. Cartridge : .308 Win.
Bullet : .308, 150, Barnes 'X' BT 30817
Cartridge O.A.L. L6: 2.800 inch or 71.12 mm
Barrel Length : 21.5 inch or 546.1 mm
Powder : Hodgdon VARGET
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 95 40.95 2549 2164 48258 7542 94.1 1.105
-09.0 96 41.41 2575 2209 49609 7630 94.5 1.093
-08.0 97 41.86 2601 2253 50999 7716 94.8 1.081
-07.0 98 42.32 2627 2298 52430 7800 95.2 1.069 ! Near Maximum !
-06.0 99 42.77 2653 2344 53903 7883 95.6 1.057 ! Near Maximum !
-05.0 100 43.23 2679 2390 55420 7964 95.9 1.045 ! Near Maximum !
-04.0 101 43.68 2705 2437 56983 8043 96.3 1.033 ! Near Maximum !
-03.0 102 44.14 2731 2484 58593 8120 96.6 1.022 ! Near Maximum !
-02.0 103 44.59 2757 2532 60253 8195 96.9 1.010 !DANGEROUS LOAD-DO NOT USE!
-01.0 104 45.05 2783 2580 61963 8268 97.2 0.999 !DANGEROUS LOAD-DO NOT USE!
+00.0 105 45.50 2809 2628 63729 8340 97.5 0.988 !DANGEROUS LOAD-DO NOT USE!
+01.0 107 45.96 2835 2677 65557 8408 97.7 0.976 !DANGEROUS LOAD-DO NOT USE!
+02.0 108 46.41 2861 2727 67450 8475 98.0 0.965 !DANGEROUS LOAD-DO NOT USE!
+03.0 109 46.87 2887 2777 69410 8539 98.2 0.954 !DANGEROUS LOAD-DO NOT USE!
+04.0 110 47.32 2913 2827 71441 8601 98.5 0.944 !DANGEROUS LOAD-DO NOT USE!
+05.0 111 47.78 2939 2878 73545 8660 98.7 0.933 !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 105 45.50 2927 2854 73438 8271 99.9 0.937 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 45.50 2656 2350 53915 8059 91.7 1.050 ! Near Maximum !
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Joined: Mar 2005
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Campfire Regular
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Campfire Regular
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I find an accurate chronograph very important when working towards max. If your speeds are in a normal range I'd be pretty comfortable. If you are getting higher than usual velocity you are generally getting the pressure too high as well.
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Joined: Nov 2005
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OP
Campfire Regular
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Thank you both for the information.
I am going up .3g grains on the Varget (just to see) and am going to try 44g of RL 15 too. I know 2750 isn't going to bounce off anything but still want to safely optimize my results.
The truth angers those whom it does not convince
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Edit: misread op.
Last edited by greentimber; 09/17/11.
RLTW
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I have loaded Etips in the 300win mag and 243 win. Nosler suggest a long jump to lands which takes up powder space and possible raises pressure. In my experience i found .030 off the lands in both rifles gave me the most consistant velocity and accuracy. I would also use slow powder with the 150gr Etip. In the 308 case i know i would start with H414/W760. My normal 308win 150gr ballistic tip load uses varget with good results but the Etip is a long bullet that has the bearing surface more like a 165gr or 180gr standard bullet.
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Campfire Outfitter
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Campfire Outfitter
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well not shot any e-tipe but get 2740fps with 168ttsx with 45.5gr vargot in a 24" barrel
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