Does the brand of brass effect load data? Like does one load shoot differently between brands of brass, or primers for that matter?
Question about brass
- Thread starter goodgorilla
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I've ran different internal case capacities through Quickload and you will get different pressure. Seating depth also plays a role in pressure. As far as shooting differently, your unlikely to notice much with a MV SD of say 20 fps at 50-100 yards, but will see a big difference on hits at say 1000 yards.
I will use mixed brass for pistol and non precision rifles. For my precision rifle, I use one brand of brass, same lor number, and sirt by weight.
I will use mixed brass for pistol and non precision rifles. For my precision rifle, I use one brand of brass, same lor number, and sirt by weight.
yes.
Different brass makers will generally have different internal volume, which changes what pressure you get out of the same charge weight in a different brand case. Brass will have different neck thickness which changes neck tension. Flash hole uniformity, consistency from case to case within a lot. and many other factors all add up to make differences matter.
On primers, yes, different brands are harder/softer hotter/colder, and change ignition characteristics, and consistency of velocity.
Does all this matter to you?
If you are loading 30-06 hunting loads 1gr above a starting load, when your goal is 2" @ 100yds - probably no concern at all.
If you are shooting, or want to shoot < .25 MOA, and/or running near max pressure... yes it matters a lot.
What are thick and thin cases? Is a thin case one that has been used several times?
Lapua and I believe FGMM cases are considered thick. correct me if i am wrong. I have seen smarter people than me state you need to down load by 4% in Lapua or FGMM or by at the least .3 grains. I never downloaded FGMM brass... But maybe I should? I personally never had any pressure signs. I just bought my first 100 pieces of Lapua and will do load development with them when I have time and the weather cooperates. I do not know where Hornady brass falls into line. I imagine Norma is "thick" as well
Are there any indicators if a brass brand is thick or thin? Sounds like some work better than others in different situations. I was planning to find a brass that I like and stick with it. My first brand I am going to try out is Norma, but at the range a few guys said that seating primers in norma can be problematic.
Military and Lapua are some examples of thicker cases. One quick test is to resize and trim your brass and then compare how much water it will hold against other brands.
So the less water means a thicker case? Because the outside of the cases have to be the same shape for a given caliber? Also, why would you want to use a thin case?
When you adjust the information on quick load fit internal capacity, it changes the pressure. Quick load has been spot on for me so far (I've only had it a month) and when O measures some case internal volumes and corrected that from the default values, I get a different number. Other factors affecting pressure would be bullet seat depth and whether or not the projectile is seated in or out if the lands.
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I was reading the ABC's of reloading, but I feel I was getting to far ahead before having my equipment set up. There have been some delays in cleaning out the room where my setup is going to be.
When you use ANY case, you start at minimum load and work up.
Change components, work up a new load.
Lapua brass isn't always the lowest capacity......the .338 brass has greater capacity than the Hornaday or Privi brass. The same load in all three types gives a velocity variation from 2800 in the Lapua cases to 2880 in the Hornady and 2950 in the Privi. These were all shooting the same 250gr SMK at the same seating depth. Accuracy with all 3 types is about the same but the point of impact is different between them all. Mixing the cases and trying to shoot groups insures a large group size. So to answer your question, yes it affects load data if you want to use different cases and duplicate point of impact. Primers will affect this as well.
Frank
Frank
Yes.
The heavier cases are thicker. Military 7.62 NATO cases and a couple of commercial cases (Federal, Lapua, PMC and Speer) are thicker than Winchester, Hornady and Remington cases.
In 308 Winchester / 7.62 NATO brass, the thicker cases are the heavier cases by weight. I did my own case volume measurements and was able to use a good array of Commercial 308 cases and Military 7.62 NATO cases with head stamps going back from the 1960's. Across the board, the heavier cases had less internal volume.
Military 7.62 NATO cases weighed in between 180-186 grains. Commercial 308 cases weighed in between 154 grains to 184 grains. The cases I weighed were weighed with the primer still in the case. You can deduct 5.0 grains for the primer weight. Some of the lightest cases were Winchester and Hornady cases, but I've found in some more recent mfg. Hornady and Winchester cases they both have cases weighing in the 170 grain range.
This is why it is a good idea to segregate cases by brand and weight. As far as weighing cases within a particular brand, I weigh them to be within a 4 grain spread of one another. This works for me. Others may disagree. I have Hornady and Winchester cases segregated in three different weight categories, 158-162, 162-165 and 168-172. Everyone has their own degree as to how OCD they want to get as far as weighing components (Brass, Bullets and Primers). It depends on how precise you want to be to try to eliminate potential flyers.
Yes, the less water capacity means less internal volume. Yes, the outside dimensions of the cases have to meet a tolerance specification so the case will chamber in any rifle.
You will run into pressure issues if you use a maximum load that was worked up in thinner, more capacity brass and then use the same load in a thicker case that has less internal capacity.
The bottom line is to start a load at a safe powder charge weight and slowly work up the powder charges and stop when you start seeing pressure signs.
