[vulcandeathbuny]

I've seen where everyone says not to use them in 223 because of the pressure difference of the 22 hornet that its intended for . But what about 300 aac blackout?

[Reloadron]

Using SAAMI maximum pressures:

.223 is 55,000 psi
.300 AAC Blackout is 55,000 psi

Give this old thread a read. (http://www.thehighroad.org/showthread.php?t=678753)

That said we have no shortage of members here who have loaded the higher pressure .223 using Remington 6 1/2 primers successfully. Watching for pierced primers and burning on the bolt face.

As we know Remington states:
In rifle cartridges, the 6-1/2 small rifle primer should not be used in the 17 Remington, 222 Remington, 204 Ruger or the 223 Remington. The 7-1/2 BR is the proper small rifle primer for these rounds.


Since the .223 and 300 AAC Blackout share the same maximum pressure (from what I read and I may be wrong) personally I would look for a better primer for the 300 Blackout. However, that is your call. I am not saying the 6 1/2 primers won't work or your gun will explode in a million pieces and kill you, I am saying that I will not encourage you doing it.

Ron

[ArchAngelCD]

I'm not sure why Remington is still producing their 6 1/2 SRP since for the most part they are only good for the 22 Hornet especially since no harm would be done in the 22 Hornet with their 7 1/2 primers.

[beatledog7]

They work great in .38SPL loads.

[ArchAngelCD]

They work great in .38SPL loads.
But Remington also has SPP so what good?

[beatledog7]

The usefulness for this application surfaces when SPP are hard to find or when you buy some 6-1/2s then realize they are not appropriate for .223 Rem.

[vulcandeathbuny]

I see lots of people saying they can be used in some pistol loads. Whoa about s&w 40

[beatledog7]

I wouldn't use them in a high pressure cartridge. I limit them to .38SPL.