Safe load for Norwegian Krag.

[Sunshineboys]

I have read about safe loads until I am pooped. So, I went to the Hogdgon site and checked their info. I will paste what I have here. I want to know, can I use a lower powder charge by a few grains without risk? Is pressure at 39,300 safe? Is there another powder which may be better suited to my reloads?
Dave
Barrel Length: 24.000"
Trim Length: 2.155"
BULLET WEIGHT
140 GR. SPR SP
CASE
WINCHESTER
PRIMER
WINCHESTER LR, LARGE RIFLE
Starting Load Maximum Loads
Manufacturer Powder Bullet Diam. C.O.L Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
IMR IMR 4350 BUY NOW 0.264" 3.030" 41.0 2,486 39,300 CUP 45.0 2,677 46,000 CUP

[butlersrangers]

Starting loads in current U.S. loading manuals will be safe in a Norwegian Krag.

IMO - Under-loaded cartridges of slow propellants are potentially a greater danger due to Detonation risk (secondary explosion).

Loading manual 'Starting charges' using IMR-4895 should be quite safe.

[Sunshineboys]

I take it that IMR4895 is a faster burning rate than IMR4350? I have bunch of that so I will try. Thanks for the advise. Dave

[Culpeper]

Here is what Sierra writes.

Powder Burning Rates and Nomenclature

In preparing this edition of the Sierra Reloading Manual, we encountered some confusion relating to the identity or nomenclature of certain powders. This is due in large part to the fact that there has never been any standardization of the abbreviations used by different manuals to identify a given powder. As an example, Reloder 7, a medium-fast burning rifle powder manufactured by Hercules (now Alliant Powder) is identified in Sierra’s loading tables as “RE-7.” In other publications, it has been listed as Re7, RL-7 and RX7. With such similar powder names or designations as Hodgdon’s HS-7 and Accurate Arms’ No.7, the stage has been set for a potentially dangerous situation. In this particular example, the three powders listed (RE-7, HS-7, and AA No.7) are all distinctly different and are not interchangeable. Because of the lack of uniformity between the various publications, we felt that some form of index or legend would prove to be beneficial.

We also now have a situation wherein powders having the “same” numerical designation are available from several different sources. Probably the best example of this is the slow-burning single-based rifle propellant known as 4350. Available now as the original IMR 4350, Hodgdon’s H4350 and Accurate Arms’ 4350, the potential for confusion is obvious. Other powders sharing this same situation are 4227, 4198, 4895, and 4831. Each of these powders is available from both the Hodgdon and IMR powder companies. Most of these are interchangeable with the similarly designated powder, i.e. H4895 with IMR 4895, but this is not always the case. The two 4831s, for example, are quite different and cannot be safely interchanged. For this reason, we recommend that loads be used exactly as they are shown in the manuals with no substitutions. If you have any doubt as to which powder is meant by a particular designation, please call our toll-free technical service line at (800) 223-8799.

The following powders are listed by their approximate burning rate, from “fastest” to “slowest.” It must be clearly understood that burning rates are not linear. There may be several powders which have very nearly the “same” relative quickness listed together, with the next listed powder being significantly different. It should also be understood that the burning rate of any given powder can vary substantially when different cartridges are being compared. Smokeless propellants are organic compounds, and are subject to lot-to-lot variations that are unavoidable during the manufacturing process. As a result, it is quite possible for a “fast” lot of a “slower” burning powder to appear to be somewhat “faster” than a “slow” lot of what would normally be thought of as a faster burning propellant. This situation, in effect, would cause these two powders to switch positions in the following chart. Bear in mind then, that these listings are subject to change depending on the particular lots of powder involved and a host of other variables that become part of the equation. In the following chart, the column on the left lists the powder manufacturer along with their full designation for the powder in question. The center column is the designation used by Sierra in the loading tables of this manual. The right column, where applicable, are some of the designations of this powder as listed in other publications. This is by no means a complete list, and reflects only those powders used in this manual.

https://www.sierrabullets.com/reload-ba ... ing-rates/

And then on to Hodgdon

https://hodgdon.com/wp-content/uploads/ ... -color.pdf

[svartkrutt]

Norwegian rule, max pressure is 3300 bar for the Krags.

[Capt. Frank]

In my Swedish Mauser, I have found, that H 4305 is much more accurate the IMR 4350.

[Bernt]

Norwegian rule, max pressure is 3300 bar for the Krags.

According to Raufoss 3500 bar is max pressure for the Krag. For Mauser (M98) and Sauer 3800 bar.

This is an article from early 90's, published in the Norwegian shooting associations magazine. It's about freebore and chamber pressure. Written by the former product coordinator of Raufoss. It's in Norwegian, but you'll see the important data.
With 6mm freebore a normal Krag cartridge have a velocity of 770m/s (2525 f/s) and chamber pressure of 3300 bar. With zero freebore, the velocity increased to 800m/s and the pressure to 4100 bar! (Max for Krag: 350 MPa = 3500 bar, Mauser / Sauer: 380 MPa = 3800 bar). Very important for handloaders to check the freebore of their rifles.

Maxtrykk1.jpg (379.6 KiB) Viewed 14355 times

[butlersrangers]

For us, who think in terms of psi, 1 bar = 14.5038 psi

3300 bar = 47,862.5 psi

Lots of 6.5X55mm 'starting-loads', in U.S. Reloading Manuals, develop well under that amount of pressure.