I thought I would run the same test we did on the 308 Winchester and 3 different primers, on the 300 Winchester Magnum.

But, with all the primers that I have. Both standard and Magnum.

Standard primers that we have are:

RWS 5341
CCI BR2
Winchester WLR
Federal 210M

Magnum primers we have

CCI 250
Remington 9 1/2 Magnum
Winchester WLRM
Federal 215

Our test rifle is the Steyer SSG 08, with a 27 inch barrel, with a Leupold VX6 7-42X scope.

Rifle rest is the TARGET SHOOTING, INC. Model 1000LP.

Bullets are Sierra 168 Match Kings.

All shots are off the bench at 100 yards.

I have included both the extreme spread and standard deviation of each load.

I still have some powders to shoot with the standard primers, and then I will repeat everything again with the Magnum primers.












































This conclude my testing with standard primers.

I will shoot the same loads with Magnum primers.

Interesting that you got some hangfires,they can be upsetting. It would be interesting to know what is going on inside the case during those few milliseconds? The ES and Sd appear to be a bit larger but not really hugely so. I was using Re22 when I was having the problem. It also looks like Es and Sd don't necessarily correlate with group size. Keep up the good work. Knowledge is only useful if it is shared.
C.G.B.

Reloaded 22 is being tested next.

Thanks for sharing the results of your testing with us! I'm curious about the brass you're using. Is it new brass every time, or the same set reloaded each time, if you're annealing the necks of your brass, etc.?

I've seen quite a drop in velocity variation with annealed necks.

Do you know what the firing pin protrusion is or how sloppy the headspace is? It seems that the hangfires are mostly with one type of primer, but ignition problems could also be related to how the pin hits the primer.

I am using 85 cases for this test. They are all fired, resized, trimmed, primer pockets cleaned, and shot again.

No annealing is done.

I do not suspect anything wrong with the rifle or its firing pin.

The test is to determine of using standard primers in a large case cane cause misfires - as we have suspected, and experienced before.

It seems certain powders are more susceptible to this than others.

WE have also seen it happens with all slow burning powders used in the larger cases - I have experienced it in the 300 RUM case with all powders.

When I test the Magnum primers, that should rule out any problems with the rifle or its firing pin.

I have updated all results with standard primers.

Very surprising that the H870, which is a very slow burning ball powder, had no hangfires at lol.

Saeed:
Again, some damned tight groups!
Wish I could shoot that well.

For light bullets I use the '06,
in the 300 Win, I've gone to 200gr Game Kings.
But, I only use it to hunt elk with.

Thank you very much for sharing this info with us.
George

Hopefully next week I will get some results with Magnum primers.

Amazing how "cold" the RWS primers are.