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Question?
monticellotdm
Member Posts: 256 ✭✭✭
Thinking of starting to reload my own. 270 wsm, After looking over some of the load data many of the powder charges only fill the case some as low as 60% if that is so... then there may be almost 3/4 of an inch air space in the shell case or more. If holding the rifle down from an elevated position... dropping the volume of powder to the bullet and leaving the air space between the primer and powder... does this large void cause any pressure or velocity changes when fired? If so should I choose a powder combination that more fully fills the cartridge?
Comments
"does this large void cause any pressure or velocity changes when fired?"
Yes. Usually when testing low volume powder charges, we often elevate the rifle skyward in order to place the powder against the primer before lowering it towards the target. Even then the potential for inconsistent or catastrophic ignition exists.
"If so should I choose a powder combination that more fully fills the cartridge?"
Of course, that's what the logical result should be. It's been proven time and again by accuracy shooters that a full case of appropriate powder yields the most consistent and repeatable results.
Ramshot Magnum will fill the case to 100% when a Berger 150 gr. VLD is seated to magazine length according to my notes. Re-25 is still the best with the heavier bullets in my opinion. The case capacity is not used when lighter bullets are selected. This is a point all too often missed by reloaders. They opt for lighter bullets and higher velocities and poor efficiency. Larger case capacities need to use heavier bullets.
Best.
Primers, like powder, vary by manufacturer so the proper methodology is to start low and work your way up slowly watching for signs of pressure, to the most accurate load.
Best.