The Firing Line Forums - View Single Post - Does a primer make that much difference??

**Mike Irwin** · July 17, 2012, 11:58 AM

I had loads worked up for my modified .243 that would cut 1/3" groups at 100 yards all day long.

I switched out the primers for CCIs one day because my gunshop was out of the ones I normally used (Federal).

Groups opened up to well over an inch.

When I went back to Federals, my groups shrank back to where they should have been.

July 17, 2012, 11:58 AM	#23
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,380	I had loads worked up for my modified .243 that would cut 1/3" groups at 100 yards all day long. I switched out the primers for CCIs one day because my gunshop was out of the ones I normally used (Federal). Groups opened up to well over an inch. When I went back to Federals, my groups shrank back to where they should have been. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.