Questions about Primers.

[Baltimoreed]

My understanding is that CCIs are the hardest while Federals are the softest, don’t know how the other brands rate. But I’m more curious about which brand is the hottest, the hottest standard and hottest magnum primers. Still working on my 300blkout build and I’m just wondering if a hotter primer would give me a little more gas to operate my rifle. Anyone done or know of any primer testing to establish a rating? Thanks ahead.

[JimB..]

I think you’re looking for brisance.

Higher helps to ignite powders that resist ignition, but I don’t think changing primers will change the volume of gas produced as that’s a function of the powder chemistry.

[Baltimoreed]

I currently use regular CCIs for everything but was curious if a magnum primer would make a dif and if one brand was more potent than another.

[Burnt Fingers]

The primer is going to add as much gas as a fart in a hurricane.

1. Change gas system
2. Make sure gas system is assembled correctly
3. Adjustable gas block
4. Ream out port
5. Make sure boolits haven't clogged the gas system

I built my 300 BO on a 10.5" barrel and a pistol length gas system. If you're going to shoot subs you need a pistol length gas system.

A carbine length system and subs is almost always recipe for failure.

[jim147]

Don't forget about buffer weight.

[Burnt Fingers]

Don't forget about buffer weight.

That's a whole 'nuther rabbit hole!

[Winger Ed.]

The difference from weakest to hottest primer wouldn't change the over all pressure as much as about .2 gr. of powder would.

I'd develop a load for accuracy noticeably under the max. for the caliber.
If the .300BO isn't powerful enough for what ya want, I'd get something else, maybe in 7.62NATO.

[Norske]

Western Powders (Ramshot) published a booklet years ago that had the identical 22-250 load (except for primer) twice. The velocity with a WW primer was greater than the CCI, and the peak pressure for the WW primer was 3000psi greater. I tried their test with 36 grains of WW748 and chronographed the results. CCI primer, 3519 fps; WW primer 3647 fps. Their newer reloading manual calls for mostly WW primers with their double-base, often graphite coated rifle powders. For handguns, they use Federal primers.

[Alferd Packer]

I wouldn't say Federal primers are the softest, but they are far more sensitive which is why LEE says don't run them thru their hand primer.
A sharp bump such as dropping the tool loaded with Federals could very well result in an explosion.
A primer being forced into an undersize primer pocket could also go off and set off the whole tray full in your face.
By the way, CCI has a hard primer which is made for loading Military as well as any semiauto rifle round and should be the only thing you use.
This hard primer is also available for loading the hi pressure pistol rounds such as 9 mm, 10 mm. and .40 caliber.
They should be a must use on your shopping list. The face/hand you save may be your own. This includes ammo for all m1 garlands, m14s, and ARs and m16's.They all require the hard primer.

[Hossfly]

My 300 BO wouldn’t cycle so just upped the powder till it did. Never thought about a primer issue.

[parisite]

I think we should worry more about how to get any primers of any brand.