What CCI primer to use for super-sonic 300 blackout

[Tazlaw]

I acquired a 300 blackout, AR style and want to load for it. Lyman 50th calls for CCI #41, are there any substitutes?

I want to shoot super sonic for deer and hog hunting. Eventually I’d like to cast for this rifle. I’d also like to be able to pick up primers at local gun store. But if I have to use CCI #41, then I’ll try and find some to order.

Thanks in advance.

Taz

[JimB..]

Most folks just use what they use for 223/556, a magnum small rifle primer.

The #41 is slightly different, it’s a bit harder to ignite to prevent accidental firing from the floating firing pin, but few folks feel that the difference is material in any respect.

Start low, work up, all the usual warnings.

[Valornor]

In my experience any small rifle primer is going to perform just fine in 300 BLK supersonic and subsonic loads.





Jay Andrew
www.theballisticassistant.com

[jonp]

I've used both msrp and srp. Have not noticed much difference as the case size is not very big.

[Larry Gibson]

CCI 450 with ball powders, CCI 400 with extruded powders.

[Lloyd Smale]

I agree
In my experience any small rifle primer is going to perform just fine in 300 BLK supersonic and subsonic loads.





Jay Andrew
www.theballisticassistant.com

[ThomR]

I use whatever I can find.

[6bg6ga]

I've used the standard rifle primer as well as magnum.

[Dapaki]

It's too small of a cartridge to worry about special primers, any small rifle primer you have will light the powder.

[georgerkahn]

Sadly (for the firearms) I was present for two slam-fires. That in many military-style firearms the metal piece which hits the primer to break its anvil and ignite the powder is free floating is a major factor. Even in the course of another cartridge being advanced, the primer is most often slightly contacted; e.g., "tapped".
On both M1 Garands and M1 Carbines, I've seen the teeny-tiny impressions left.
Here, Tazlaw, is the ;) rub. For one, if the "tap" is more than it takes to set off the primer -- then the bullet will be trying to fly down the barrel -- but, with not everything in place to readily enable this -- catastrophe follows. Added are, imho, a few zillion other variables, ranging from too-high/not fully seated primers to timing defects and the like in the firearm.
*I* try my best to reduce said chances. As but one example, as while Federal primers are great in tuned single-action "cowboy" revolvers with reduced springs to, in this case, increase the percentage of cartridges firing -- they are (imho) a definite brand to stay away from in loading for any and all gas guns! To have primers which take a uniform, heavier hit -- thus decreasing immensely the chances for a slam fire or other accidental discharge -- I use NOTHING OTHER than the CCI #34 or #41 in my gas gun loading.
Just writing what *I* use, and why...
BEST!
geo256741

[swheeler]

Sadly (for the firearms) I was present for two slam-fires. That in many military-style firearms the metal piece which hits the primer to break its anvil and ignite the powder is free floating is a major factor. Even in the course of another cartridge being advanced, the primer is most often slightly contacted; e.g., "tapped".
On both M1 Garands and M1 Carbines, I've seen the teeny-tiny impressions left.
Here, Tazlaw, is the ;) rub. For one, if the "tap" is more than it takes to set off the primer -- then the bullet will be trying to fly down the barrel -- but, with not everything in place to readily enable this -- catastrophe follows. Added are, imho, a few zillion other variables, ranging from too-high/not fully seated primers to timing defects and the like in the firearm.
*I* try my best to reduce said chances. As but one example, as while Federal primers are great in tuned single-action "cowboy" revolvers with reduced springs to, in this case, increase the percentage of cartridges firing -- they are (imho) a definite brand to stay away from in loading for any and all gas guns! To have primers which take a uniform, heavier hit -- thus decreasing immensely the chances for a slam fire or other accidental discharge -- I use NOTHING OTHER than the CCI #34 or #41 in my gas gun loading.
Just writing what *I* use, and why...
BEST!
geo256741

I'm of that same school^^^^^^^

[GONRA]

GONRA also votes for CCI #34 or #41 for ALL semiauto rifles to prevent slam fires! You do NOT wanna hava Slam Fire!

[popper]

Cci srp work fine. Slam fire is not good but muzzle safety reduced danger.

[Texas by God]

My LGS carries only CCI and Winchester primers. So that is what I use in standard strength.

[6bg6ga]

Winchester standard rifle and no slam fires.

[rcslotcar]

For an AR go with CCI 34 or 41, bolt action any thing else.

[ShooterAZ]

I've been using the regular CCI 400 SRP's for decades, never had a problem in any of my AR's or 30 Carbines.

[hockeynick39]

CCI 450 with ball powders, CCI 400 with extruded powders.

^^^^^^^^
Definitely this.