Different brass.....different powder weight ?

[colinbentley]

I have been reloading using my recycled Winchester brass using 38.5 grains. However I bought 100 Norma brass a while ago and thought I would try it. The Norma is slightly heavier than Winchester so by how much should I reduce my powder load ?

[bigfellascott]

I wouldn't bother (I load all sorts of diff brass with the same loads for that particular cal) - hunting use here.

[bladeracer]

I have been reloading using my recycled Winchester brass using 38.5 grains. However I bought 100 Norma brass a while ago and thought I would try it. The Norma is slightly heavier than Winchester so by how much should I reduce my powder load ?

The weight doesn't matter.
Measure how much powder both cases hold.
If they're the same don't worry about it.
If Norma is a little smaller in capacity then knock a little off your charge.
But your charges were a long way from maximum loads I believe?

[Chickenhawk]

Yep, it's not the weight. It's the internal capacity that'll matter.

Likely to be slightly different between brands.

But saying that it's slightly different between individual cases of the same anyway so unless you are already batching your brass by capacity it's not going to be any different to what you're already playing with really.

[Gwion]

Weight of the casing for any given cartridge is likely to be heavier for a smaller internal capacity. This also means that the walls/webbing may be thicker and there fore stand slightly more pressure. ADI brass is known to be heavier duty in both weight and pressure tolerance than many other factory offerings. None of this is a guarantee.

If you are changing any part of your load recipe, i would be inclined to back off and do a quick re-working of the load. How much i would back off is entirely due to how close i already was to a book max load and what cartridge i was loading. Say, for 7-08 i might knock off 1 grain and work back up in 0.3gn increments, for 223 i might back off 0.5gn and work back up in 0.2 increments looking for any sign of pressure. I would load 3 rounds per increment to get a hint of an idea of accuracy. All goo, i would then just confirm the load as previous.

Mind you, doing all this takes me about 1-2 hours in the back paddock and not a week having to load and drive to a range to test, etc, etc....

If you are well back from max load, it is probably fine just to load 15 rounds, shoot 3 groups of 5 to confirm accuracy and check pressure signs before doing a full rework but the likely hood is that a different case will have some effect on accuracy. Is it enough to bother you? that is entirely up to your own standards or expectations of performance. Me??? I reckon i need all the help i can get so i try to have my load and rifle shooting spot on.

[colinbentley]

Thanks Gwion you have probably echoed my thought s on the subject. Thank you to everyone who took the time to give me advice. As I am 1.5 grain s lower than the recommended maximum load I think I am safe to stick with that load. if the projectile is just touching the powder in the case, is that good or bad ? This really is a fascinating "hobby".

[bladeracer]

If the projectile is just touching the powder in the case, is that good or bad ? This really is a fascinating "hobby".

If there are no signs of pressure then it's neither good or bad.
Some of my full-power loads actually compress the powder into the case when seating the bullet.