Primer difference?

[dukedurham]

I happened upon a few hundred Remington 6 1/2 small rifle primers, however, all load manuals list .223 loads using 7 1/2 primers. What is the actual difference between the two if any? Are these ok to use in place of the 7 1/2's? Duke

 

[Cheechako]

The 6 1/2 and 7 1/2 are both small rifle primers. The old 6 1/2 was used in the smaller cartridges like the 22 Hornet, 218 Bee, etc. When the high intensity cartridges like the 222 R, 222 Rem Mag and 223 were introduced, Rem brought out the 7 1/2 which has a slightly thicker cup and is a little hotter to better ignite the larger powder charges.

Ray

 

[Bob3700]

Duke,

That thicker cup is pretty important as it will keep the primers from piercing at 223 pressures.

Do your bolt face a favor and only use the 6 1/2s on lower pressure 223 loads.

Bob

 

[MKLOWERY]

Cheechako,
Could you please contact me, I work for a manufacturing company that is interested in working with you on developing ammunition. I do not mean to be blunt but we are eager to speak with you, my contact info is as follows...Mathew Lowery,Alps South Corp.,727-528-8566 ext. 315, mathew@easyliner.com, Thank you.

 

[Winchester69]

From the Remington site:

In rifle cartridges, the 6-1/2 small rifle primer should not be used in the 17 Remington, 222 Remington or the 223 Remington. The 7-1/2 BR is the proper small rifle primer for these rounds.

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