Confused -Big Surprise From Nosler Published Data

Marshal

Beginner
Jan 3, 2008
9
0
Went to the range today (no wind, sunny, 68 degrees f) with my .243 ( Savage 12 BVSS). Loaded up some Win Brass, Fed 210M, Nosler 95gr BT, VH-N-560 (from 42.0 to 44.5 book max) COL 2.700". Max velocity was 2892 over my chrono. What gives???; the 42.0 load went 2743 fps. Very disappointed, accuracy was 1 moa no better.
 
Welcome to the wonderful world of Chrono`s.

I found there is very often a drop of 100 fps or so between my rifle and the various load book claims. Some of it is due to the fact our chambers and bores are not as tight as the SAAMI spec test barrels used to work up the data. The barrels in some books also are 24 or 26" and mine are shorter. Different powder lots can make a difference, I`ve heard there is a tolerance of +/- 5% (10% over all) on the burn rate of canister powder and this can translate into a matching change in the result we get.
If you don`t use the same brand and style components as the book you`ll get a different result. Sub`ing a Hornady 150 gr bullet for a Nosler 150 gr as an example may or may not raise pressures or velocities. from those in the manual you are working from.
I`d try another powder and see if you find the result closer to the books. Don`t expact to reach the same velocity, if you are within 50 fps or so I call it good. If you have a different barrel lenght from the one used in the manual you can`t do a fair comparison. There is no way to tell with any certanty how much loss or gain you have due to the added or shorter inches.
 
Marshal

The Nosler manual (Bless it's heart) comes from the same place that brought us 6# trigger pulls. It's been my experience that you can load up a bit (starting at minimum) and watching closely for pressure signes untill you get to almost the velocity they show for max loads. That is about what your rifle and chamber will perform at. The folks at Nosler are understandably concerned that someone will overdo it for their rifle and !!! :x
Good Hunting
Elkhunt :grin:
 
Is your concern the accuracy or the speed? Unless you have a pressure measuring device or have had many years experience loading, don't go above the max suggested loads. Some folks seem to think they can read the brass like flattened primer or the bolt was hard to open. Rest assured by the time you think you might have a pressure problem, you do!!!! Years ago I use to go to the edge with loads but have realized the small gain you might see on the chrono doesn't really gain you anything in the field. If I want more speed I can try different powders, go to a lighter bullet, get a longer barrel or go to a larger case.

Now if you do want to go higher than the max loads, you are on your own. No one will step forward if you have a problem. Watch your chronograph as the loads go up. 42.0 gave you 2743fps. With that powder in that size case you should expect 25-45fps per half grain of powder. So your 2892fps follows what one would expect. Your chrono can be a very useful tool to your loading. If you add another half grain and you vel goes up another 30 fps you are still in the good area. It has been my experience that with certain powders/case capacities you will reach a wall where adding more powder doesn't increase the velocity by the same amount, you get no increase or you could actually loose some vel. When any of these things happen, you have gone pass the safe pressure. When you look in a manual for start/max loads check vel gain vs powder added see if your rifle/load follows. Several manuals will give you various amounts of powder/vel. Check all you can.

Just remember all loads you see on the net aren't necessarily safe and what may be safe in one rifle/load combo may be an overload in another. Be safe and enjoy what loading can do for you. Don't be a velocity nut it really doesn't do that much if anything in the field.Rick.
 
Thanks for the replies. My concern is both accuracy and speed. I try to obtain 1/2 moa from my loads and as much velocity as is safely possible,i.e not going over book max. I guess I was just surprised that i was almost 300fps slower with the same max charge of 44.5 N-560. I expect the book to be somewhat in the ball park. For example, I shot the same components with 40 to 42 gr of H414. I got a best MV of 3052 fps with 3/4 moa at 44gr and got 2947 fps with 42 gr. Hodgon's load data I used suggested 3100 fps was doable. Alas, my results were close and accuracy can be tuned.

In the end I think N-560 perhaps isn't an optimal powder for the .243 with 95 grainers. I will refine the H414, then try IMR 4064 and IMR 4350. thanks.
 
Marshal":1sk4spqo said:
Thanks for the replies. My concern is both accuracy and speed. I try to obtain 1/2 moa from my loads and as much velocity as is safely possible,i.e not going over book max. I guess I was just surprised that i was almost 300fps slower with the same max charge of 44.5 N-560. I expect the book to be somewhat in the ball park. For example, I shot the same components with 40 to 42 gr of H414. I got a best MV of 3052 fps with 3/4 moa at 44gr and got 2947 fps with 42 gr. Hodgon's load data I used suggested 3100 fps was doable. Alas, my results were close and accuracy can be tuned.

In the end I think N-560 perhaps isn't an optimal powder for the .243 with 95 grainers. I will refine the H414, then try IMR 4064 and IMR 4350. thanks.
.................You nailed it here!!.....Certain powders, in certain rifles, with certain bullets and components, will not deliver the book velocities you`re looking for............With each rifle being its own fingerprint, experimentation with as many powders and bullet combos are necessary. N560 doesn`t seem to be the best performer, with that bullet, in YOUR rifle! H-414 if memory serves, is a faster burner than N560, which worked alot better! Experiment further with various powders with about the same burn rate as the H-414!!
 
Marshal,
That 300 fps difference is why we call the Chronograph the "de-liar". Seldom do most reloaders use exactly the same component listed in the loading books, Consequently, your results may vary. Here are a few things that can lower your velocity.
Thin Brass (such as Winchester)
Cold Primers (such as CCI)
Bullet design
Seating depth
Short barrel (this is a big one)
Cold temperatures (most loading books assume 70 degrees)
Loose chamber, or worn throat.
My advise is to play around a little bit with a few different powders. A faster powder might be the answer, especially if you have a short barrel.

As Rick said, sometimes you can add more powder, and achieve a lower velocity. In my experience this is usually because you are using a slow powder in a short barrel. The bullet has exited the barrel, before all the powder has had an opportunity to burn. However, these same increases in powder charge will continue to provide a velocity increase in a rifle with a longer barrel.
 
To pipe in and give my .02 worth, I load strictly for accuracy. The velocity is what it is. Once I get the accuracy, I load up a bunch and shoot them over the chrono to get an average FPS so I can set the scope, and figure out the ballistics, i.e. do I go 1" high or 2" high at 100 yds, for a 200 - 300 yd zero. The recipes just guides, I never expect to achieve what they got.
 
Yhis is what quickload predicts.


Cartridge : .243 Win.
Bullet : .243, 95, Nosler Part.Sp 16315
Cartridge O.A.L. L6: 2.710 inch or 68.83 mm
Barrel Length : 26.0 inch or 660.4 mm
Powder : Vihtavuori N560

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 80 37.60 2497 1315 27642 8404 84.0 1.650
-18.0 82 38.54 2562 1385 29532 8711 85.6 1.608
-16.0 84 39.48 2628 1457 31557 9012 87.2 1.567
-14.0 86 40.42 2694 1531 33725 9304 88.7 1.527
-12.0 88 41.36 2760 1607 36050 9586 90.1 1.488
-10.0 90 42.30 2827 1685 38544 9858 91.5 1.447
-08.0 92 43.24 2893 1766 41221 10117 92.7 1.401
-06.0 94 44.18 2960 1848 44095 10362 93.9 1.359
-04.0 96 45.12 3027 1933 47185 10593 95.0 1.317
-02.0 98 46.06 3094 2019 50512 10807 96.0 1.278
+00.0 100 47.00 3160 2107 54092 11004 96.8 1.239 ! Near Maximum !
+02.0 102 47.94 3227 2197 57953 11182 97.6 1.202 ! Near Maximum !
+04.0 104 48.88 3293 2288 62118 11340 98.3 1.166 ! Near Maximum !
+06.0 106 49.82 3359 2380 66618 11477 98.8 1.131 !DANGEROUS LOAD-DO NOT USE!
+08.0 108 50.76 3425 2475 71448 11592 99.3 1.098 !DANGEROUS LOAD-DO NOT USE!
+10.0 110 51.70 3490 2570 76649 11684 99.6 1.065 !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 100 47.00 3334 2345 66092 10935 99.9 1.139 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 47.00 2932 1814 43479 10436 89.1 1.367
 
POP...hmmmm, now that is very interesting. I will be completley honest and admit that i have at times, based on my rifles and my ability to read/measure pressure ( expansion ring compared to factory, primers etc) load to what I believe is safe in my rifles. I may just have to make some adjustments to the load, given that I didn't see any visible signs of pressure at 44.5, thanks very much.
 
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