Different powders

[KnotRight]

I have a bunch of the "standard" rifle powder on the shelf but some manuals call for powder that is hard to get.


Less say that The Hornady manual calls for 30 gns of Reloader 7 which has a burn rate of 146. And the 30 grns is a starting load. I do not have any Reloader 7 but have IMR 3031 (burn rate 148), Benchmark (149) and H322 (157).


Would you use any of those other powders with the same starting loads? If not, would you adjust the starting load?


I am finding this problem mainly with 7.62x39 and some 45-70 loading data.

[Hick]

There are a few places on the internet where you can find tables that show "equivalent" powders instead of just burn rates. ADI has one, among others. I have used them for this same problem. HOWEVER, there are disagreements about what is equivalent (I've done some comparisons). So, if you are going to try something, start by trying to match the starting load and work up very carefully

[trails4u]

My general rule of thumb is to start painfully low with unknown loads. If I can find it in a manual, verify it by another manual, and it makes sense...then I'll start mid-load. If not...then it's mouse farts and up from there. Powder and primers are really cheap compared to blown up guns and medical bills....

[C. Latch]

The Hornady manual calls for 30 gns of Reloader 7 which has a burn rate of 146. And the 30 grns is a starting load. I do not have any Reloader 7 but have IMR 3031 (burn rate 148), Benchmark (149) and H322 (157).


Would you use any of those other powders with the same starting loads? If not, would you adjust the starting load?



It doesn't really work that way. It's close, but not exact.

If you see promising load data for powder #95 and you don't have any but you do have powder #94 or #96, which are 95's neighbors on the burn rate chart, it's almost certain that they will work well.


It is, however, much less certain that the data for #95 can be used for its neighbors. Burn rates are dynamic, subject to changes across the pressure spectrum, so that while #94 may be faster at .45 ACP pressures than #95, if you load it to .44 magnum pressures they may switch places and what you thought was a slower powder may actually be faster. Worse, while #94 may show a max load of, say, 30 grains, the equivalent max load for #95 may be 31 grains, or it may be 27, as one powder may be more or less dense than the other

Add those two factors and what you get it this: load data is powder-specific. There's no way to change this. Your best bet is to look for more data (there's tons of reliable data online now: hodgon, alliant, ramshot, VV, and Nosler, for starters, all have data online, not to mention the treasure trove that is Castpics) or, if you simply cannot find what you need, take your starting loads and reduce them even further before starting with your 'other' powder.

Also, if you can't find data for the powder that's similar to the one you do find data for, look at other cartridges that do well with powders in the same burn rate range and see if you can find data for those other calibers where both of the powders in question are used for the same cartridge, and see how they compare to each other in charge weights, but be sure and do this across a wide spectrum of bullet weights, not just one weight.

Even then....be careful.

[mdi]

Ummm, nope. Burn rate charts just tell you the order of "burn speed". Number 148 may be faster than number 149, but how much? The only thing charts tell you is which is faster than another, not specific speed. For a new reloader, using powder charge data from another powder is unwise, if not sometimes dangerous. Look in your manual(s) and stick with data suggested for a specific powder. Also you can go to a powder manufacturer's web site and get info for just about any load you'd wanna use...

[OS OK]

This is a wonderful example of why some of us try to attain and hang on to the 'Older Loading Manuals'…you are building your own libraries of information that tends to disappear as time goes by.

[Wayne Smith]

In most cases you can go to the powder maker's website and find a load, if not e-mail them. I'm also willing to e-mail the BulletSmith's at Sierra with similar questions. Many times you will find that there is a good reason why you aren't finding the load you want - incompability of the powder in one way or another precludes it from being used in that application.

No, relative burn rates change from one caliber to another and from one list to another. No way I would use them for a powder charge.

[Ola]

My general rule of thumb is to start painfully low with unknown loads. .. If not...then it's mouse farts and up from there.

I hate to say this, but with some rifle powders (= slow burning) you maybe shouldn't do that. When developing loading data the powder company makes pressure measurements. The minimum load is the first load that generates constant and expected pressures. Under that there is a some kind of a problem.

[dverna]

I find that an email to the manufacturer gets a quick response. Why take chances when it is not necessary?

[leeggen]

Powder burn rate charts are all over the place, and they place powders in different places of order. some powders will be listed and on the next one won't show some of the powders listed else where. Some show say 130 powders some will show 150 others will show what they want. progress forward very carefully, you may only get one mistake!
CD

[mdi]

After rereading most of the posts in this thread the consensus seem to be, don't do it...

[Wayne Smith]

After rereading most of the posts in this thread the consensus seem to be, don't do it...

... And that there are better ways of accomplishing the purpose.

[Yodogsandman]

https://www.natchezss.com/alliant-reloader-7-powder-3950.html

follow down on the list for reloader 7
http://www.cabelas.com/product/shooting/reloading/reloading-powders-primers%7C/pc/104792580/c/104761080/sc/333152280/alliant-smokeless-powder/731761.uts?destination=%2Fcatalog%2Fbrowse%2Freloa ding-powders-primers%2F_%2FN-1109591%2FNs-CATEGORY_SEQ_333152280

http://www.butchsreloading.com/shop/reloading-components/555-alliant-rifle-powder-reloder-7-1lbs-.html

[Don Fischer]

There is only two powder's I know of that has the interchangeable data. W760 and H414. There are a couple more you could do it with but I would encourage you not to do it. I assume your using cast data. I've got some very old manuals and I might be able to find you different data. I have a suitcase full of Super Ballistite I found data for, can't remember where I found it now though. Also have most of a keg of Pistol Powder #6 I found data for. But I would not guess or experiment using other data's charges. Throw the powder burn chart away!