I'm loading 308 and 243. Powders are Varget, IMR and H4895, 8208, IMR 4064 & 4451. The Coronavirus dried up standard primers at Bass Pro, so I took some Large Rifle Magnums. None of my loads are near Max, so what should I do about adjusting the charge for the change in primers? Is 10% a safe bet.
Standard vs Magnum Rifle Primers
- Thread starter gnfiter3
- Start date
I would load 3-5 with normal powder charge and chrono and compare. Just because a magnum primer is hotter, does not mean that your charge now is going to be.
Sometimes a switch to a magnum primer just disrupts your powder burn characteristics enough that your load may end up slower, rendering it way less efficient.
You can always pull bullets if you do not like what you see.
Sometimes a switch to a magnum primer just disrupts your powder burn characteristics enough that your load may end up slower, rendering it way less efficient.
You can always pull bullets if you do not like what you see.
You'll see about a grain of difference. Mag primers are better than nothing,... but the softer you reliably start the fire the more consistent your loads will be. Now that said using ball powder in low temps begs for mag primers. Powder choice is a major factor.
If your chargers are any where close to pressure they can put you over the top.
I’d reduce the charge.5 to 1 grains lower and try it to see if it matches original velocity.
I’d reduce the charge.5 to 1 grains lower and try it to see if it matches original velocity.
