Brass weight to load weight correlation?

[moosekiller99]

I have exclusively used Winchester brass in my Ruger M 77 that I weight sorted years ago. As I am running out of usable pieces I decided to begin load development with the Remington brass that was also sorted but never used in this rifle. The Rem brass is heavier than the Win brass by 8-15 grains in some pieces which means lighter charges to obtain similar velocity and pressure. Using some math I calculated that the 61.0 load I use in the 187 gr Win brass should be reduced to 58.0 grains in the 197 gr Rem brass. I of course will work up to this load weight and chrono each incremental load as I approach my math predicted load. I know there are numerous variables that I am ignoring in this process, but I am hoping my end result shows a close correlation between the two variables (brass and charge weight). The current components are: 3000 fps using Win brass; Win Primer; 150 grain Nosler Partition and 61.0 grains of Reloder 26. Same load with Berger 150 grain VLD's is 3010 - 3020 fps with nearly same POI at 100 yds.
So, any thoughts whether my methodology is sound?

 

[rsmithsr]

go pull the trigger, the paper will answer your question.
typically it is volume not brass weight that is used.

 

[birdiemc]

And be sure to let us know how it works out. I like all the experimenting that goes on around here.

 

[Jud96]

Brass weight doesn't mean much. Case capacity is what you need to be concerned with.

 

[bruceleroy]

Ive been able to maintain load consistency over 4 types of brass: Hornady, Federal, LC LR and Match, Winchester.
There has been no real difference in impact locations, group sizes or pressure signs (none).

 

[rsmithsr]

I doubt you are shooting small groups 1/4 moa or less at any long range distance.

Ive been able to maintain load consistency over 4 types of brass: Hornady, Federal, LC LR and Match, Winchester.
There has been no real difference in impact locations, group sizes or pressure signs (none).

 

[User4302021]

I don't know where 1/4 moa groups come into any of this... but to the OP, I'll bet you end up about 0.6 grains lighter in your loading to hit the same average in velocity.

 

[bruceleroy]

I doubt most hunters, or even most shooters, are actually getting consistent 1/4" groups. No cherry picking allowed. At some point it would turn from showing off harvested animals to holes in a target. One matters a lot more than the other. I do submit that my average group size did NOT increase when changing brass. I am sitting at a consistent 3/4" average groups size across different brass brands.

 

[J E Custom]

I have exclusively used Winchester brass in my Ruger M 77 that I weight sorted years ago. As I am running out of usable pieces I decided to begin load development with the Remington brass that was also sorted but never used in this rifle. The Rem brass is heavier than the Win brass by 8-15 grains in some pieces which means lighter charges to obtain similar velocity and pressure. Using some math I calculated that the 61.0 load I use in the 187 gr Win brass should be reduced to 58.0 grains in the 197 gr Rem brass. I of course will work up to this load weight and chrono each incremental load as I approach my math predicted load. I know there are numerous variables that I am ignoring in this process, but I am hoping my end result shows a close correlation between the two variables (brass and charge weight). The current components are: 3000 fps using Win brass; Win Primer; 150 grain Nosler Partition and 61.0 grains of Reloder 26. Same load with Berger 150 grain VLD's is 3010 - 3020 fps with nearly same POI at 100 yds.
So, any thoughts whether my methodology is sound?

Cases with less volume (Powder capacity) will normally produce more pressure) so you are right to reduce your load. I recommend that You fully Prep the cases and separate them buy weight or volume which ever method you use. I believe that If you full length size, prep the primer pockets, trim to the same length, and weight sort, they will be very close in volume. If the out side of the case is identical, and they weigh the same the volume will be very very close. for sure it is better than not weight sorting. The times that I have selected cases that were exactly the same instead of within 1 grain lots, accuracy has improved over the ones that were within 1 grain. This proved to me that It was a viable method and I didn't have to mess with liquids, chemical wetting agents, spent primers and the general messiness of the process.

No matter how you do it, consistence in all areas is beneficial, and no matter if you change brands or use different batches of cases the weight/volume need to be checked. Buy loading one batch and documenting the weight/volume of the last batch of cases sited in with. If you check the new brass cases after sorting, you might get lucky and have one batch of the new brass that matches the old cases and reloading for the same results will be easy.

J E CUSTOM

 

[rsmithsr]

maybe read the whole post.
it has the post I was talking about.

I don't know where 1/4 moa groups come into any of this... but to the OP, I'll bet you end up about 0.6 grains lighter in your loading to hit the same average in velocity.

 

[User4302021]

maybe read the whole post.
it has the post I was talking about.

Nope, not there.

 

[rsmithsr]

I doubt you are shooting small groups 1/4 moa or less at any long range distance.

"Ive been able to maintain load consistency over 4 types of brass: Hornady, Federal, LC LR and Match, Winchester.
There has been no real difference in impact locations, group sizes or pressure signs (none)"
of he is on your ignore list..that is YOUR issue.

.

Nope, not there.

 

[User4302021]

I doubt you are shooting small groups 1/4 moa or less at any long range distance.

"Ive been able to maintain load consistency over 4 types of brass: Hornady, Federal, LC LR and Match, Winchester.
There has been no real difference in impact locations, group sizes or pressure signs (none)"
of he is on your ignore list..that is YOUR issue.

.

Umm...my post about not knowing what 1/4moa has to do with it, was in response to YOUR post you just quoted.

However, this is now the third forum we share where you have earned a place on my ignore list.

 

[rsmithsr]

since you have an issue with simple English, I will return the favor
ignore list here you come

Umm...my post about not knowing what 1/4moa has to do with it, was in response to YOUR post you just quoted.

However, this is now the third forum we share where you have earned a place on my ignore list.