209 Primer Length variations

[Marty1]

I was curious as to what variations exist in the length of some 209 primers I commonly use with BH209, so I took 25 each of Remington STS, Fiocchi 616, and CCI 209M Primers and measured their lengths.

ABOVE: Rem STS - Fiocchi 616 - CCI 209M
Interesting how each brand differs slightly in design.


Here were the results:

Remington STS Primers

Mean: 0.29496 inch
S.D.: 0.00080

Fiocchi 616 Primers

Mean: 0.29792
S.D.: 0.00089

CCI 209M Primers
Mean: 0.29762
S.D. 0.00102


DEFINITIONSSD): Shows how much “variation” there is from the "average" (mean). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values. The Standard Deviation(SD) is simply derived from taking the square root of the Variance. In the math world of statistics, squaring makes each term positive(+) so that values above mean do not cancel values below the mean.

 

[exMember]

I wonder why some primers come with that round edge and others do not?

 

[Marty1]

I wonder why some primers come with that round edge and others do not?

I don't know...good question. I never paid much attention to their edges until I zoomed in on them. In the world of reloading, a round edge may be a little more forgiving when seating the 209 if your primer pocket is dirty in the bottom. I can remember having to clean my primer pockets on occassion after several reloads to get the primers to seat flush again. A round edge may also help to funnel and direct the flame.

 

[johnp0341]

There is also a difference in width, CCI's won't fit in my Savage Breech plug, Winchesters will.

 

[Marty1]

There is also a difference in width, CCI's won't fit in my Savage Breech plug, Winchesters will.

CCI :?: :?: ...209M's :?:

:?: Which Winchester primer.... :?: