Primers- small rifle vs small rifle magnum

[Hawkeye7br]

School me on the practical difference. I bought 10k a few years ago and largely load rifle cases from 223-6.5 Creedmoor, but have always used small rifle. I need to back off a grain or two?

 

[Rookie]

 

[STFU]

Good info. Thx!

 

[dieselrealtor]

I can't remember where I ran across it, but there was a video of a small ammo manufacturer that had equipment to measure pressure, possibly velocity as well.

He loaded several rounds with the exact same charge with standard & magnum CCI primers if memory serves me correctly.

No appreciable difference in pressure or velocity in that test.

 

[Hawkeye7br]

Good info from all, thank you. I'll do a limited test to see if the thicker cups ignite properly.

 

[Bill2905]

In 223 bolt guns, I find little difference in performance between CCI 400 standard and CCI 450 magnum small rifle primers. I have also used a lot of Remington 7-1/2 small rifle magnum primers and haven't seen any noticeable difference. If I loaded 223 for the AR platform, I would choose the CCI 450 or the Remington 7-1/2 for their thicker cup.

I recently developed a load for my 6BR F-Open rifle with Varget and CCI 400 primers because I had a lot of them. After I had settled on a load, I was curious if CCI 450 primers would shoot differently. I loaded 15 rounds with each primer type and fired them in alternating order over a chronograph at two side by side targets. The CCI 400 group was a little smaller, average velocity was the same but the SD was 33% smaller (8 vs 12). It was a very limited sample size and it's quite possible I would have gotten different results on another day.

 

[Hawkeye7br]

Great info Bill, many thanks.

 

[Robert Richardson]

I for years have used the Winchester primers. Box states standard and magnum loads. I believe there is a lot of hype about the dangers of using magnum primers with standard loads. A primers job is to light the powder, as long as it does that, it's fine. The power charge causes the pressure, not the primer. I don't back off the powder when using magnum primers and I've never see any pressure problems and never a big bunch of velocity change. Actually I prefer to use the magnum primers, they work with any powder out there.
It's kinda like saying that more spark from my spark plugs will blow up my car engine. Never seen a high output coil damage a engine. Just saying. It ain't rocket science.