Range Report – Standard Small Rifle Primers vs Magnum Small Rifle Primers, in 223

[btefft]

Range Report – Standard Small Rifle Primers vs Magnum Small Rifle Primers, in 223

I was wondering about the difference in velocities of reloads using Standard Small Rifle Primers as compared to reloads using Magnum Small Rifle Primers. I know for a fact, that Magnum Large PISTOL primers produce higher velocities than Standard Large Pistol primer. I experienced it while shooting rubber bullets (no powder) from a 44 Mag case with only a primers, no powder. I wondered if the same was true of small RIFLE primers.

I used Federal Standard Small Rifle Primers and CCI Magnum Small Rifle Primers. I wished I could have used Standard and Magnum primers of the same brand, but didn’t have one brand of both kinds of Small Rifle Primers.

I shot them from my Olympic Arms AR15 with its 16 inch barrel.
All reloads contained 20.0gr (trickled for exactness) of H4198 powder.
All reloads contained 55gr SPBT bullets purchased from Berry’s.
I used a Chrony F1 Master Chronograph to get their velocities.
Sky Screens 15-20 feet from muzzle. So, muzzle blast shouldn’t have been a factor.

My hypothesis was that Magnum Small Rifle Primers (MSRP) would produce higher velocities than Standard Small Rifle primers (SSRP) – same as Large Pistol primers.

My hypothesis was not supported by my experiment. I found that:
the velocity of a bullet fired with a SSRB was, on the average, 2767.
the velocity of a bullet fired with a MSRB was, on the average, 2722.

My conclusion is that MSRP, with their thicker cup, contains less primer accelerant (powder).

Here’s the data. Velocities are in chronological order (so I can more easily so the range), not the order produced when the string was fired. However, the 2 slam fires are where they happened.

Standard Small Rifle Primers

Stan Sm RI Prim
20.0 ! - H4198
3/21/2009

1 2677
2 2715
3 2738
4 2741
5 2763
6 2770
7 2773
8 2781
9 2781
10 2787
11 2804
12 Slam Fire
13 Slam Fire
14 2810
15 2828

2766.77
Average

Give or Take
61.23

Magnum Small Rifle Primers

Mag Sm RI Prim
20.0 ! - H4198
3/21/2009

1 2651
2 2675
3 2682
4 2684
5 2688
6 2694
7 2721
8 2734
9 2735
10 2737
11 2751
12 2756
13 2771
14 2776
15 2781

2722.40
Average

Give or Take
58.60


BTW - The thinner skinned SSRP produced two slam fires during their string of shots. The thicker MSRP had none. So, if using SSRP use good range safety – as you would do anyway. But, I often point the AR upward as I depress the lever to send the bolt forward, loading the first round of a new mag. I was on the porch of the cabin myself and my brothers built on our hunting property. I’m glad I didn’t have any slam fired then, or I’d shot a hole in the roof.

Hack

[VaFisher]

Very interesting report to say the least, keep up the good work and keep us informed while you are at it sir.

[Dave R]

Consider this an anecdote...because its just something I read on the Internet.

What I read was that CCI (the only makers of mag primers for small rifles, I believe) got a bit embarrassed because everyone else's primers were hotter than theirs, and their primers didn't light some of the ball powders as well as they should. So they introduced the magnum primers and priced 'em a titch higher.

Then everyone else started saying their primers were good for either standard or magnum "loads."

Speer (owner of CCI) only specifies magnum primers for SOME of their loads. The ones that their standard primers didn't ignite as well.

Most other primer mfgrs specify their primers for any load.

Take it for what its worth.

I did a somewhat similar test, using Winchester WSR primers head-to-head with CCI small rifle mag primers in a load that calls for the mag primers. The WSR primers yielded identical velocity, and 'maybe' a bit better accuracy.

Hardly scientific, but another data point.

[Magnum Wheel Man]

it's alway fun to expriement, but by not using the same brand, you already have an apples to oranges comparision...

I personmally have a very wide selection of primers, & the only small rifle magnum prmers I have are CCI's, so I can't dispute DAVE Rs statement???

I'd be more interested ( & it would be of more current relavance ) to compare 4-5 brands of small rifle primes all using a standard powder...

[Wulfmann]

To my knowledge there is no industry standard regarding magnum primers as to what they should do or be.

Wolf sells a Small rifle magnum and according to Widener's it is the same solution as the small rifle standard but the magnum has a thicker cup to prevent slam fires.

Now Wolf has come out with a small rifle primer for .223 but I can find no information (as of yet) as to what that means.
Have they renamed the magnum SR .223???
Seems logical and if so, do they plan to release a true magnum primer along the lines of the CCI #41 military primer????

I use the current Wolf SRM in both my Daewoo and Les Baer AR15V and they are as good as any primer I have used.

I have not used the CCI#41 but I have used the #34 large rifle military and it is smoking hot more than any magnum primer.

My point is that differences in brands has had more variation than magnum over standard of the same brand in my experiences.

Wulfmann