How much does brand of brass affect loads?

[Roddy]

Something I rarely see mentioned in reloading manuals is the type of brass thy use to determine maximum loads as well as their most accurate loads.

I am using Federal .308 brass. It's not popular brass but it's what I have and it seems to be accurate. My concern is that because it is thicker walled than most brass it will have a lower safe maximum than the brass tested. I watch for pressure signs but it would be nice to know how much difference brass makes. Plus when I see someone's favourite load online, and it is well within the safe operating range for my rifle, if they are using Lapua brass I want to know if I can duplicate it.

 

[Longshot338]

As far as accuracy is concerned you are looking for consistency. If a brass with a given headstamp has a large variance in weight after processing, you will be looking at differing internal volumes from piece to piece. This will result in different pressures and velocities. On another note; if the brass in the neck is thinner or thicker, the neck tension holding the bullet will also differ. All of this leads up to inconsistent pressure development.

Some headstamps will be larger in general as well. By this I mean that if one headstamp averages less weight than another you will find that one generates a higher pressure load.

Also look for primer pocket depth, uniformity in flash hole diameter, and thickness of the base.

Some personal observations of brass I have dealt with:

Lapua is the best. No contest. Most consistent, long case life with proper sizing, everything is perfect. Comes at a price; by that I mean price tag.

Federal is cheap. Less brass in the base; larger internal volume. Takes a bit more powder to generate the same pressures and velocities. Some batches/calibres have split after a couple reloads even with minimal sizing.

Winchester: overall pretty good. The only complaint I have is inconsistent weights. In 243 and 308 I have had large spreads of weight in a batch.

Remington is my favorite of the common non-match brass. Pretty good on all fronts; very long case life.

Hornady I also like. I have heard lots of complaints of it being soft. I have only ever used 243, and it has been great.

Don't forget; the process by which you treat the case will have far more effect on accuracy. If you take cheaper Federal cases, minimally size them, trim, chamfer, deburr them, sort by weight, deburr the flash hole, etc... you can get better accuracy than untreated unsorted Remington brass.

My $0.02

 

[Roddy]

As far as accuracy is concerned you are looking for consistency. If a brass with a given headstamp has a large variance in weight after processing, you will be looking at differing internal volumes from piece to piece. This will result in different pressures and velocities. On another note; if the brass in the neck is thinner or thicker, the neck tension holding the bullet will also differ. All of this leads up to inconsistent pressure development.

Some headstamps will be larger in general as well. By this I mean that if one headstamp averages less weight than another you will find that one generates a higher pressure load.

Also look for primer pocket depth, uniformity in flash hole diameter, and thickness of the base.

Some personal observations of brass I have dealt with:

Lapua is the best. No contest. Most consistent, long case life with proper sizing, everything is perfect. Comes at a price; by that I mean price tag.

Federal is cheap. Less brass in the base; larger internal volume. Takes a bit more powder to generate the same pressures and velocities. Some batches/calibres have split after a couple reloads even with minimal sizing.

Winchester: overall pretty good. The only complaint I have is inconsistent weights. In 243 and 308 I have had large spreads of weight in a batch.

Remington is my favorite of the common non-match brass. Pretty good on all fronts; very long case life.

Hornady I also like. I have heard lots of complaints of it being soft. I have only ever used 243, and it has been great.

Don't forget; the process by which you treat the case will have far more effect on accuracy. If you take cheaper Federal cases, minimally size them, trim, chamfer, deburr them, sort by weight, deburr the flash hole, etc... you can get better accuracy than untreated unsorted Remington brass.

My $0.02

Oh I was under the impression Federal cases had less internal volume and required less powder. That is the information I am looking for. I have heard of a formula where people reduced powder charge a certain amount based on reduced case volume.

I do trim, chamfer, deburr the flash hole, etc.

I know my brass isn't the best. I was just wondering how load data for my brass compared to load data for other brass.

 

[H4831]

There are a great many theories out there, but most of them are not proven.
How much does some variance in case weight effect the shooting? With cases that are within ten grains of each other, I will wager that an average hunter/shooter with his sporting rifle can not detect any difference, in accuracy or velocity.
I once weighed out five 243 cases which were ten grains heavier than five other 243 cases, loaded identical loads on them all, then fired the five heaviest and the five lightest, in two groups, all shot over a chronograph.
In theory the heaviest should have had the highest velocity, because of less room for powder, than the lightest. In reality the cases that were lightest in weight actually made about 30 fps higher velocity than did the loads from the heavier cases.

 

[bigedp51]

Something I rarely see mentioned in reloading manuals is the type of brass thy use to determine maximum loads as well as their most accurate loads.

I am using Federal .308 brass. It's not popular brass but it's what I have and it seems to be accurate. My concern is that because it is thicker walled than most brass it will have a lower safe maximum than the brass tested. I watch for pressure signs but it would be nice to know how much difference brass makes. Plus when I see someone's favourite load online, and it is well within the safe operating range for my rifle, if they are using Lapua brass I want to know if I can duplicate it.

Just about every reloading manual I have lists the test rifle and the components used meaning the type case used for the reloading data. These same reloading manuals also tell you when reloading to start low and work up your loads. Your cartridge cases are just part of the equation, if you look in the Lyman reloading manuals many times you will see a universal receiver and test barrel are used. The test barrel will have a chamber and bore at minimum SAAMI dimensions, meaning this test setup will generate the highest chamber pressures. If the manual lists a specific firearm used then a strain gauge will be glued to the barrel and a cartridge of a known chamber pressure will be used to calibrate the strain gauge. This is why loading data varies between manuals as an example the Hornady manual for the .223 using 55 grain bullets lists 23.2 grains of H335 as a max load but the same load with 55 grain bullets in the Sierra manual for the AR15 lists 25.7 grains of H335 as a max load.

Bottom line, you will learn more about your rifle and components by starting at the suggested starting load and work up until pressure signs tell you to stop.

So pick a brand of brass, buy enough from the same lot to satisfy your needs and work up a load. And always remember the load data you see that other people post online are "ball park" and will not be the same in your firearms.

Below are Quickload charts using Lake City 5.56 cases with 30.6 grains of H2O capacity and another brand with 28.0 grains of case capacity and 6,000 psi difference in chamber pressure. This pressure data is for a AR15 chamber with its longer throat and not for a shorter throated .223.

Now make a work up load after reading the link below.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

And by making up workup loads and measuring case head expansion and learning to read your primers you will be much better off.

Below the maximum safe load of Habanero chili peppers that can be mixed with your cattle feed.
So always remember $hit happens when reloading so always be safe.

 

[Kelly Timoffee]

Actually brand I doubt effects as much as people think.

See what F-class are using, it is all over the board, but what isn't all over the board is their meticulous case prep, that is where the accuracy is.Some brands require a bit less prep and work but in the end it all comes down to consistency in your brass not type.

 

[CV32]

As far as accuracy is concerned you are looking for consistency.

Consistency is the foundation. Quality brass will have it. But it is just one variable of many and how much it really matters will depend on the shooter and their intended purpose.

 

[Roddy]

Thanks for the advice everyone. I do take the reloading manuals information with a grain of salt.

For the load I am working on Sierra lists a much lower max load than Hodgdon. Plus they are seated extremely short so I think that further separates the data from my situation.

The reason I asked this question because for .308/178 AMAX/Varget best accuracy loads seem to be very similar for everyone. Mine are a little higher so I was going to try bringing them down in case I missed a good load and to increase brass life.

My primers look like something between the far left one and the second one from the left in that picture. No sticky bolt handle either.

bigedp51 I don't have a blade micrometer so I guess that is the next thing I have to buy.