Another noob question on powders


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Afy
May 1, 2008, 07:04 AM
The vihtavouri manual states that the N165 powder has the same/simmillar burn rate to the Vectan Tubal 8000 powder. So can one substitute the Tubal for N165 using N165 load data for a given bullet wieght?

Thanks once again for the knowledge and guidance.

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steve4102
May 1, 2008, 07:44 AM
No. Burn rates are not absolute. They can vary from cartridge to cartridge and from burn chart to burn chart. Swapping data from one powder to the next can get you into real trouble.

Here is an example. In this chart VV 120 and IMR 4227 are neck and neck. Data for the 7.62x39/125gr bullet for N-120 in 26gr max. Data for 4227/125gr bullet is 18.5gr, big difference.
http://www.ramshot.com/powders/

You may get lucky and it will work out for you, then again you may not.

ricciardelli
May 1, 2008, 09:01 AM
Never directly substitute ANY component when reloading without doing a new work-up.

Unless, of course, you have two things:
1) A damn good medical insurance policy;
2) Enough money to buy a new rifle and the stuff to go with it.

Afy
May 1, 2008, 01:14 PM
Ok that clears one thing up... despite a good medical policy and money to replace the rifle...will not try it.

The problem is that the Vectan manual sucks. They provide no ranges.. just one value, and seem to only like Speer bullets.

rcmodel
May 1, 2008, 01:22 PM
The one value is the max load with that bullet.

Subtract 10% for a starting load & work up.

rcmodel

scrat
May 1, 2008, 01:25 PM
But only 10%. subtracting to much will have ill effects. these effects could be on accuracy. then if your shooting an autoloader, you could have problems with the round cycling. so only subtract 10% and work up

Waskawood
May 3, 2008, 10:23 AM
I don't mean to hijack this thread. I just bought a .204 and so many manuals only supply data for a particular brand of powder and bullet manufacturer. My question is, if they say that I can use 24 grains of brand X powder with a 32 grain Hornady V Max, can I use the same 24 grains of powder with a 32 grain Sierra or do the different bullets raise the pressure to an unsafe starting point? How about going from a 39 grain Sierra to a 40 grain Hornady? Thanks for any help and sorry if I hijacked the thread.

MinnMooney
May 3, 2008, 10:49 AM
Burn rates may be the same but there are lots of other factors like density. This is why "steve4102"'s answer is correct. Those two powders have vastly different volume per weight.

ForneyRider
May 3, 2008, 03:10 PM
Been on here quite a bit, plus a lot of other reloading forums.

RCModel gives very safe, smart advice.

Burn rate charts are good for comparing ranges. Like VV's burn chart says N165 is pretty close to RL22. So if I get bored of RL22, can't find it, or whatever decide to go with a VV powder, I know N165 is the one.

But I think that is as far as the comparisons go. They may act differently at different temperatures, etc.

H110 and W296, for magnum pistols, are sometimes said they are the exact same powder. But who knows? Were they the same before the acquisition? I think W231 and another Hodgdon powder (HS-6, or HP38) might be the same as well. But I will still use the exact powder from the recipe.

Looking at some load data for my 7mm Mag, the loads were for RL19, RL22, and RL25. They were all about 150-200fps difference and 2-3gr difference. But I wouldn't swap data on even those.

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