6.5 primer size .

[Closeone]

When ordering ammo from copper creek, their offering large and small primer in 6.5 creedmoor. What’s the reason for two different primers in the same caliber?

 

[jepp2]

What’s the reason for two different primers in the same caliber?

Main reason, by using a small rifle primer, the opening in the case head is smaller. So if someone were to load the cartridge to a higher pressure than SAAMI allows, the primer pocket will take longer to loosen to the point it can't be reloaded. Same scenario with a large rifle primer, less reloads due to the larger opening = less strength.

Secondary reason, since the primer charge is part of the total charge, if the small rifle primer ignites the powder in a more consistent manner with less charge than the large rifle primer, ES and SD will be improved and vertical dispersion at distance will be less

 

[KMart]

Jepp pretty much summed it up. If you are not reloading, you should get some of each and compare them for accuracy and use what shoots best.

If you reload, the small primer would be the way to go.
If you reload, for now, get the brass that matches your largest primer supply.

 

[22DASHER]

My next few builds will be based on LR pockets because SR is obsolete around here. Definitely recommend building off of what you have, 99% (probably 99.9%) of shooters wouldn’t see the difference.

 

[Kracken McGraw]

I would read some threads on primer piercings before you buy the small rifle primer brass. Your bolt and firing pin may not be set up for the srp.