Velocity Differences Between Brands of Brass

[Jdillon]

Went to the range today to test some loads in my 220 Swift. Had 20 rounds each loaded with new Remington and Norma brass. The Remington loads averaged 100 fps faster than the Norma. Anyone else ever experience this?

 

[rcmodel]

Sure.

Almost every brand of brass has different case capacity. (Thicker or thinner brass)

The one with less capacity runs higher pressure with the same powder charge, and that equals higher velocity.

rc

 

[Jasper1573]

Yep, I started out using Winchester brass and then fell into some Lake City once fired stuff. I found the LC gave me about 100 fps more velocity than the Winchester...similar results for Remington brass in my experience.

 

[bobnob]

I found that the Win brass has greater capacity. You have to use more powder to get the same velocity.
However I also found you can use more powder before hitting pressure signs and when pushed to the same extent, you got higher velocity again.

I imagine it makes sense that greater capacity, pushed to the same pressure, equals higher velocity?

 

[rcmodel]

Yep.

More powder = more gas expanding to push the bullet longer.

rc

 

[gamestalker]

Yes, this is why I prefer Remington brass. I find it noticably better for compressed charges of slow buring powder too.