Krag Collectors Association Forum

Dear KCAF members,

I will try to answer properly to your technical questions this weekend.
Best regards

'Parashooter' - 'Donki1967' resides in France and may not have available some of the rifle powders that are commonly used in the U.S.A. with the .30-40 Krag cartridge.

He does have N-140 and N-160 on his reloading bench and asked for some data using these propellants.

Do any of these charge weights of N-160 show better efficiency and burning performance in your calculations?

butlersrangers wrote: ↑Mon May 03, 2021 5:19 pm. . . Do any of these charge weights of N-160 show better efficiency and burning performance in your calculations?

Not efficient even with full case. The biggest problem with such loads is wasted powder blown out the barrel. If we have plenty of cheap powder, efficiency isn't critical. When terribly inefficient, unburnt kernels in case and barrel can fall into action during extraction and make a mess.

WARNING! These are software estimates - NOT LOADING DATA!

Cartridge : .30-40 Krag
Bullet : .308, 180, Sellier-Bellot SPRN 2937
Cartridge O.A.L. L6: 3.089 inch or 78.46 mm
Barrel Length : 30.0 inch or 762.0 mm
Powder : Vihtavuori N160

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.124% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

[Focus on penultimate collumn, "Prop.Burnt %]
Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-11.2 88 39.50 2033 1651 23828 4366 79.3 1.992
-10.1 89 40.00 2058 1693 24587 4447 80.0 1.966
-09.0 90 40.50 2084 1735 25372 4527 80.7 1.940
-07.9 91 41.00 2109 1779 26184 4607 81.4 1.914
-06.7 92 41.50 2135 1822 27023 4686 82.1 1.889
-05.6 93 42.00 2161 1867 27891 4765 82.7 1.864
-04.5 94 42.50 2187 1912 28789 4843 83.4 1.840
-03.4 95 43.00 2213 1957 29717 4921 84.1 1.816
-02.2 96 43.50 2239 2004 30678 4998 84.7 1.792
-01.1 98 44.00 2265 2051 31673 5074 85.3 1.768
+00.0 99 44.50 2292 2099 32703 5150 86.0 1.745
+01.1 100 45.00 2318 2147 33769 5225 86.6 1.722
+02.2 101 45.50 2344 2197 34873 5299 87.2 1.699
+03.4 102 46.00 2371 2247 36017 5372 87.8 1.677
+04.5 103 46.50 2397 2297 37202 5443 88.4 1.655
+05.6 104 47.00 2424 2348 38431 5514 88.9 1.630

Compare to N140 -

Cartridge : .30-40 Krag
Bullet : .308, 180, Sellier-Bellot SPRN 2937
Cartridge O.A.L. L6: 3.089 inch or 78.46 mm
Barrel Length : 30.0 inch or 762.0 mm
Powder : Vihtavuori N140

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.316% 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

-13.2 73 33.00 2130 1813 26317 4373 98.2 1.911
-11.8 74 33.50 2156 1859 27264 4431 98.5 1.885
-10.5 75 34.00 2183 1905 28236 4488 98.8 1.860
-09.2 76 34.50 2210 1952 29235 4542 99.0 1.835
-07.9 77 35.00 2236 1999 30260 4594 99.3 1.811
-06.6 79 35.50 2262 2046 31316 4644 99.5 1.787
-05.3 80 36.00 2289 2093 32406 4692 99.6 1.763
-03.9 81 36.50 2314 2141 33532 4737 99.8 1.740
-02.6 82 37.00 2340 2189 34694 4779 99.9 1.718
-01.3 83 37.50 2366 2237 35895 4819 99.9 1.695
+00.0 84 38.00 2391 2285 37134 4857 100.0 1.674
+01.3 85 38.50 2416 2334 38413 4892 100.0 1.650
+02.6 86 39.00 2441 2382 39734 4925 100.0 1.625
+03.9 87 39.50 2466 2431 41097 4958 100.0 1.601 ! Near Maximum !

Here's some real load data, from Vv's guide. Not for .30/40 but the very similar .303 British. I see good correlation of charge/velocity with the N140 QL estimates shown above. Starting load could be OK for Krag. Maximum load might be a bit stiff. I'd likely stop at 39 grains with my Krag, sooner with good group.

.303 British
Test barrel: 600 mm (23½”), 1 in 10” twist
Primers: Large Rifle
Cases: Remington, trim-to length 56,20 mm (2.213)
Bullet
Weight [g] [grs] Type/Name Mfg C.O.L. [mm] [in.]
11,7 180 Spitzer Sierra 78,0 3.071

Powder...Starting load .....Maximum load
Type Weight [g] [grs] Velocity [m/s] [fps] Weight [g] [grs] Velocity [m/s] [fps]
N140 2,33 36.0 683 2241 2,57 39.7 739 2425

Thank you 'Parashooter, that should be very helpful.

'Donki1967' has N-140 propellant in his reloading supplies.

I guess, if I was in his situation, I would give 36 grains of N-140 and the S&B 180 grain (.308") projectile a trial in the .30-40 Krag.

I admit that I have never had good results with this N160 powder, which I also tested in my SM 6.5 X55...

Hi,

Tomorrow is an other range day, so I hope having better results!
For the moment I only vary one element, namely I slightly increase my load to see.
I have taken your advice into account, but after analysis I think that I have an aiming problem associated with too low loads, and certainly I've not the best powder for this old Lady.
For memory N160 Vhitavuori.

Regards

Hi,
Just went back from the range, the results are noticeably better than expected...
A good picture is better than a long speech, so what do you deduct please?
BTW, I have not found residues in the bore, in contrary of using the same powder in my Swedish Mauser.
Regards

On my pics, do not read POI, but POA
Regards

'Donki' - I like the photo of your very tidy reloading bench.

I would call it, "A French Bench"! (Which rhymes nicely in English).

That is a fine aluminum handled "Rosalie", you have, hanging on the shelf.

That little pig is wise to hide! (In the U.S.A., we call such a bayonet, "a pig sticker").