What's the effect of using heavier brass?

[Old Rooster]

ANY change you re-work back up to best node or pressure,which ever comes first.
If I stay with the same make of brass I weigh brass to make sure it's very close to old brass.Only then will I use my proven load.

 

[WYOHTF]

why don't you give me your measurements and I will do the leg work for you with QL, you should be within .1 grains.

This right here is why this forum is so slick
Good on you sir

 

[Valek]

correct, but if you have the h2O data, then your velocity I can get a pretty good prediction of what charge you need to accommodate the less or more case volume. And it should be measured after using your die because you can alter the h2O capacity if you resize it from fire formed... unless you are smart enough to set your dies to just bump the shoulders and neck enough

Hi, Waveslayer. You've mentioned H20 weight a couple of times. The OP mentioned the difference in volume (capacity) as estimated by the difference in weight of powder. Are you suggesting the use of H20 because of its known specific gravity? Just trying to improve my minimal knowledge base. Thanks!

 

[QuietTexan]

Mainly because it's a liquid so you avoid packing problem variances inherent in using powder where grain shape varies greatly.

Two different purposes for volumetric measurement - case sorting, and case volume for load projections. H2O capacity is a commonly accepted standard for brass cases that gives a decent comparability across time and place, QL uses it to predict what pressures will be so it needs to be a straight volume in water.

For sorting a group of cases you can use alcohol, a mixture of water and alcohol, kerosene - any of those liquids will suffice to identify case to case variance.

 

[Valek]

Mainly because it's a liquid so you avoid packing problem variances inherent in using powder where grain shape varies greatly.

Two different purposes for volumetric measurement - case sorting, and case volume for load projections. H2O capacity is a commonly accepted standard for brass cases that gives a decent comparability across time and place, QL uses it to predict what pressures will be so it needs to be a straight volume in water.

For sorting a group of cases you can use alcohol, a mixture of water and alcohol, kerosene - any of those liquids will suffice to identify case to case variance.

Thank you, QT. I've occasionally compared volumes using water and alcohol just out of curiousity with no application. Appreciate your comments, especially the explanation re: QL. Thanks, again.

 

[waveslayer]

Hi, Waveslayer. You've mentioned H20 weight a couple of times. The OP mentioned the difference in volume (capacity) as estimated by the difference in weight of powder. Are you suggesting the use of H20 because of its known specific gravity? Just trying to improve my minimal knowledge base. Thanks!

H2O is used to measure internal case volume by weight. You can mix alcohol, but if you use water right no need to mix it. I use syringes from work to measure water. You want to avoid air bubbles, that's why people mix alcohol.

Once you get that internal volume you can apply that to figure out pressure on QL. That's why case weight doesn't matter, it's the internal case volume.

I do this for new once fired brass to figure out what I need to reload it to so I have the same velocity and POI as fire formed brass.

This method works for all types of brass as well. See the attached picture. I used this method for a .308 175 SMK using Federal, Lapua and Winchester Brass.
Off the top of my head Lapua uses 43.7 gr of Varget and Winchester uses 44 gr. Can't remember Federal but it was around those numbers give or take .3 grains. SD was 4 and ES was 12 or so. Just a quick single shot test.

PM if you need any help to further explain the madness .

So bottom line case weight means very very little unless you're hiking after a sheep!

 

[skipglo]

Be prepared for an interesting POI shift.

 

[waveslayer]

Be prepared for an interesting POI shift.

See above post

 

[Valek]

H2O is used to measure internal case volume by weight. You can mix alcohol, but if you use water right no need to mix it. I use syringes from work to measure water. You want to avoid air bubbles, that's why people mix alcohol.

Once you get that internal volume you can apply that to figure out pressure on QL. That's why case weight doesn't matter, it's the internal case volume.

I do this for new once fired brass to figure out what I need to reload it to so I have the same velocity and POI as fire formed brass.

This method works for all types of brass as well. See the attached picture. I used this method for a .308 175 SMK using Federal, Lapua and Winchester Brass.
Off the top of my head Lapua uses 43.7 gr of Varget and Winchester uses 44 gr. Can't remember Federal but it was around those numbers give or take .3 grains. SD was 4 and ES was 12 or so. Just a quick single shot test.

PM if you need any help to further explain the madness .

So bottom line case weight means very very little unless you're hiking after a sheep! View attachment 329562

 

[Valek]

Thank you, Waveslayer. Before I burden you with a PM, I think that I should do a bit of reading, eh? And I must unlimber my old chronometer and get in a little practice with it, too. I appreciate your offer of PM guidance, and hope to take you up on it soon. (It'll have to be soon: the older I get, the slower I get, and man have I gotten slow!)

 

[waveslayer]

Thank you, Waveslayer. Before I burden you with a PM, I think that I should do a bit of reading, eh? And I must unlimber my old chronometer and get in a little practice with it, too. I appreciate your offer of PM guidance, and hope to take you up on it soon. (It'll have to be soon: the older I get, the slower I get, and man have I gotten slow!)

don't feel bad or old, this is a hobby, so I enjoy it

 

[SSgt G Cody]

In slightly heavier brass, I would size, then start load 2-3gn less than before. Build up in .5gn increments until pressure signs begin. Then look for best accuracy node. It should be fairly close to best load with other brass.