^^Especially with temperature sensitive powders. And temperature stable powders are not immune to temperature swings. A load developed in 50°F with a known temperature stable powders may not be safe in 100°F. Add a suppressor, and pressure increases. Add wet weather, and pressure increases.

I developed a load in hot weather, with a suppressor and it was close to over pressure. A day the weather was cool, but was very wet, with mist in the air, and the brass was popping primers out.

If one of your tools in your bench bag is a large, rubber mallet, you're probably loading too hot.

Helpful thread - thank you.

Use a chrono...... + velocity equals + pressure. Can't have one without the other.

or pay the man and be done it

Removed a few things to narrow something down on a question I have for you. On one of my rifles, I'm getting similar to your Bottom row, but the primers aren't nearly that flat. I'm getting a clean/polished (if you will) ejector spot on my brass, but there's no real gouge or sharp edges, just a shiny circle. I'm getting it in my loads, and even factory loads but chalked it up to possibly soft brass?? Any ideas there?

ZK, it depends on the rifle and cartridge you are shooting. What rifle and what round are you shoot? Plus any info on your loads, brass, bullet, etc. What you describe is an ejector mark on the case head or an ejector swipe. I've seen some rifles leave an ejector mark even on mild loads, so it's not a 100% fail safe way of knowing you have reached pressure. Most AR-10's will leave a very big ejector mark on the case head, (including my 308, even with mild to medium loads). Some of the bolt action bolts I have seen have 2 ejector plungers, and will show a dual ejector mark 100% of the time. I know this, so reading the case head ejector swipe for pressure is a false indicator for those rifles. At that point, I look for sticky bolt lift (almost always a sign of over pressure) and use common sense to know when you are at or over max. I generally know with most calibers where that max pressure point is with the same components I use often. When I make a change of components or I'm trying something new is when I kind of start from scratch with data and look for the pressure signs.

It's a 7WSM in Remington 700 action. 1:8 twist brux barrel. Suppressed. Accuracy is definitely there, just always had that clean polished circle on the brass. The hotter the load, the shinier it seemed to get.

Brass is Winchester and Federal. I do keep the different brasses separated.
Federal 210M primers.
Berger 180 VLD hunting
Seated at mag length which is deep. Only thing I wish I would have done differently was build it on a long action.

For a while I was loading with some R22, which I found to be unstable in huge temp swings. Initial load work up was around 55 degrees temps and was running slightly over book max for 180gr berger VLD. I want to say it was right at 63.1gr of powder if I remember correctly. Once the summer hit, I started seeing very flat primers, but no powder creep out of the primer pockets like your second row pic. The bolt wasn't too sticky, but I could definitely tell a difference with the R22.

This past year I swapped to some 4831sc in 70ish degree temps, but stuck to my lower node mainly due worrying with the ejector marks at higher temps possibly. Now that it's hot out, I need to try some hotter loads I believe.

A suppressor will generally leave an ejector swipe also. It raised the pressure some in and increases the dwell time while under pressure.