Flattened primer question

[winmagman]

I just got back from the range today and I have a question. I had loaded some 200 gr. Accubonds over Re 22 and some H-1000 for ladder testing in my 300 win mag. I started at 68.0 grs for the Re 22 and went to 72.5 grs. in .3 gr steps. With the H-1000 I started at 74.0 grs and went to 79.0 grs in the same .3 gr. steps. I noticed that all the primers looked flattened (compared to unfired primers). I also had some factory stuff that I shot some of after I finished my tests, they also looked flat.
Finally to my question, as I'm new to reloading and have a strong desire to keep my head on my shoulders, is this a normal occurance or an indication of to much pressure? The bolt never got stiff during extraction and there were no extractor marks on the brass but I'd feel a little better with some guidance from the experts so what do you think?
Thanks in advance
Chris

 

[jcpython357]

Chris, If the factory stuff looked the same as the reloads, and the bolt wasn't sticky, I wouldn't worry about it, what are the factory loads and the rifle your using? Jay

 

[winmagman]

Jay, I'm shooting winchester supreme failsafes (180 gr) in a savage 112 bvss 300 win mag.

 

[Mark_in_utah]

I can understand your concerns for flattening the primers as being the first indication of overpressure, but it's important to note what a flattened primer looks like.

If the eddge of the primer is rounded down as it dips into the primer pocket, the primer isn't "flattened". It's natural for most all of the primer to be pushed back against the bolt. You expect that. You only need to be worried if the primer is COMPLETELY mashed back against the bolt with sharp edges.

My gunsmith doesn't look for a flattened primer as a pressure sign. He looks for a stiff bolt or a pierced primer.

I've been working up some loads for my .338 RUM, and so far I haven't found a top-end! I run out of space before the pressure goes too high on WC872, which is similar to H870. 103 grains is pretty much a compressed load. WC852 (4831) works good and so far I'm up to 93 grains behind a 250 grain Gameking. 3077 fps. I could probably fit 100 grains in the bottle, which would get me up around 3200 fps.

Mark in Utah