Load data

Elkman

Handloader
Apr 4, 2010
4,555
36
POP

I know that you have ran a quickload calculation for several folks here I wonder if you might do the same for me. I am working on a new load for my 7 mm STW and am finding conflicting information in my loading manuals. I have been using H-1000 for several years with good results. I am wanting to try some longer range shooting and have not had good luck with H-1000 with the 160 Accubonds. I have bought some RL 25 and according to some of my manuals I can load it the same as the H-1000. It is slower burning than H-1000 but other manuals show it being loaded at least two grains lighter? So I thought you might be able to help. As an old guy I really don't understand quickload but I can read the outputs and at least get some starting values. If you could run RL-25 with a 160 AccuBond type bullet I would a appreciate it very much. Any other infor relating to the difference between 25 and 1000 would also be appreciated. I need a starting medium load and maximum load.

Thanks Bill
 
Elkman,

The conflict in your loading guides is related to the fact that different barrels and different primers, as well as other differing conditions affect the outcome. Also, lot-to-lot variations in the propellants affect the outcome of the tests. Finally, bear in mind that you can't make a precise extrapolation from one bullet to another. Having said that, the data generated can be useful in suggesing powders and charges that would be acceptable for a given weight of bullet, provided you work up carefully, watching for pressure signs.

Some slower powders and maximum charges suggested by QuickLoad include: 93.5 g VN 560; 82.0 g Magnum; 76.5 g IMR 7828 SSC; 94.0 g US 869; 85.0 g Retumbo; 81.,5 g H 1000; 79.0 g RL 25; 80.0 g MagPro. You would want to drop back at least five percent on each of these and work up slowly to ensure that they are safe in your rifle.
 
Dr. Mike

Thank you for the info. My current load is 81 gr of H-1000 with the 160 TSX, with no pressure signs whatso ever. I am trying to give the Accubonds a good try but the H-1000 doesn't work so well with them and Scotty suggested that I try the RL 25 so that's my interest there. I had looked at data and found it inconsistent that's why I came to the guys here on the forum. Just this morning I have found two burning rate charts one showing RL-25 as a little slower than H-1000 and another (from here) shows it a little faster. The barrel was originally a 7mm Weatherby and has a very long throat so that is even another component that will effect pressure etc. Any way you have given me a starting point so I can load up some test ammo and try it out.
Thanks again for the help!!!!!
 
The burn rate charts are relative. They can suggest alternatives, but one needs to be careful drawing too many inferences from them. They are subject to the conditions of the test that determined the relative rates, and that information is seldom made available. In any case, Scotty gave you some good advice about the RL 25. I included data from a number of other powders that are commonly available in North America so that you can consider them if the RL 25 does not work out. Do bear in mind that RL 25 is somewhat temperature sensitive.
 
Dr. Mike

when you mean temp sensitive do you mean high temps, or both hot and cold? I am careful about leaving my ammo laying about, particularly on hot days. But what about cold and what is cold?

Have a great day!!!!!!
 
Many powders in cold weather exhibit markedly lower velocities, just as many powders (usually the same ones) exhibit pressure spikes in higher temperatures.

I often hunt in -30 C weather. Consequently, I like to test POI for my hunting ammunition before the hunt. Chronographs can give aberrant readings in excessively cold temperatures, so not even the chronograph readings can be taken as absolute. I have arbitrarily opted to avoid conducting experiments when the temperature drops below -15 C. In part this is pragmatic because my solvents freeze at that temperature, but it does avoid strange readouts on the chronograph.
 
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