Load development on new cases
- Thread starter Camoman1
- Start date
It takes about 3 firings to fully form the case to your chamber, use a lightly oiled rag to put a light coat of oil on your cases before each firing, this will help the brass slide and form to your chamber dimension easier.
You can do preliminary load testing on virgin brass, but you will find the load will slightly change once the brass is fully formed
You can do preliminary load testing on virgin brass, but you will find the load will slightly change once the brass is fully formed
You paid a pretty penny for those cases so why would you needlessly load them for no good reason? Just prep the necks and you are good to go.
And yes, only a very silly person would oil cartridge cases before firing. Some days I think Sunray is back .......
I don't think you would have that problem with Lapua brass. I don't even bother neck sizing them, just load and shoot.
Oh dear. He just SUNRAY'd this thread
- Location
- Prince Albert, Sk
Lapua cases are ready to load, I however check the necks and usually size them(necks only) due to the fact that you don't know how roughly that blue box has been handled and uniforming them up isn't going to hurt a thing and ensure consistent neck tension, just depends how fussy you are.
diametions
Full length resizing will reduce case dimensions each time the case is resized and the case will be smaller than the chamber each time the cartridge is fired.
And if you are only neck sizing and want the case to conform to chamber dimensions your way behind the times. The vast majority of competitive shooters full length resize.
A full length resized case should fit the chamber like a rat turd in a violin case. Meaning give the case some wiggle room to let the bullet be self aligning with the bore.
Below Kevin Thomas of Team Lapua USA, and member of the rat turd in the violin case club.
Below Erik Cortina of Team Lapua USA, and member of the rat turd in the violin case club.
Below is from the 1929 British "Textbook of Small Arms" and tells you to keep the chamber free of oil or grease. At this time the British used the Base Crusher system of measuring chamber pressure. The copper crusher was located at the base of the case and the case was "oiled" to read actual chamber pressure. And with a "dry" chamber and cartridge case the pressure/bolt thrust was 40% to 50% less.
And now more "facts" about lubing cases.
You Canadians deserve a little sunray from time to time, after you chased him south of the border and we now have him in so many American forums.
Full length resizing will reduce case dimensions each time the case is resized and the case will be smaller than the chamber each time the cartridge is fired.
And if you are only neck sizing and want the case to conform to chamber dimensions your way behind the times. The vast majority of competitive shooters full length resize.
A full length resized case should fit the chamber like a rat turd in a violin case. Meaning give the case some wiggle room to let the bullet be self aligning with the bore.
Below Kevin Thomas of Team Lapua USA, and member of the rat turd in the violin case club.
Below Erik Cortina of Team Lapua USA, and member of the rat turd in the violin case club.
Below is from the 1929 British "Textbook of Small Arms" and tells you to keep the chamber free of oil or grease. At this time the British used the Base Crusher system of measuring chamber pressure. The copper crusher was located at the base of the case and the case was "oiled" to read actual chamber pressure. And with a "dry" chamber and cartridge case the pressure/bolt thrust was 40% to 50% less.
And now more "facts" about lubing cases.
You Canadians deserve a little sunray from time to time, after you chased him south of the border and we now have him in so many American forums.
Last edited:
nomad 68
CGN Ultra frequent flyer
My apologise for maybe not being more precise and detailed in my first post to this thread as I tend to forget there are different levels of knowledge in load development
All manufactured brass, regardless of manufacture is undersized, maximum working pressures cannot be obtained until the brass as been fired several times and is fully formed to the chamber, IT IS DURING THIS FIREFORMING PROCESS and ONLY DURING THIS PROCESS it is safe to lightly oil the case to help it form perfectly to the chamber dimension.
It is a fairly common practice used in changing case dimensions such as 220 Russian in to a PPC used in benchrest, it also holds merit when changing the neck of an standard cartridge to an AI cartridge.
All the process is used for is to help the case form to precise fit of the chamber and is not a requirement,
For those who maybe interested in taking their load development skills to a higher level, there are many elite shooting members on here and I think most are very open to sharing their knowledge in how to make consistent accurate loads
All manufactured brass, regardless of manufacture is undersized, maximum working pressures cannot be obtained until the brass as been fired several times and is fully formed to the chamber, IT IS DURING THIS FIREFORMING PROCESS and ONLY DURING THIS PROCESS it is safe to lightly oil the case to help it form perfectly to the chamber dimension.
It is a fairly common practice used in changing case dimensions such as 220 Russian in to a PPC used in benchrest, it also holds merit when changing the neck of an standard cartridge to an AI cartridge.
All the process is used for is to help the case form to precise fit of the chamber and is not a requirement,
For those who maybe interested in taking their load development skills to a higher level, there are many elite shooting members on here and I think most are very open to sharing their knowledge in how to make consistent accurate loads
I've never used an oiled case for reasons mentioned by others but for spits and giggles I googled the idea and sure enough one guy recommends it in his article for a magazine h ttps://gunsmagazine.com/fireforming-brass/. I still don't like the idea as other methods seem to work well for me.
