Overpressureconditions in factory ammo???

[MarTay6]

I am a novice reloader, but have been studying for a long time, so when I start to reload, I'd be capable- safe- and effective.
I have a new rifle that I just shot for the first time last week- I've been working on getting it together for 2 years... it's a 6.5 Creedmoor, based on a Savage Single Shot Target Action, tuned and trued by Fred- at Sharpshooter Supply, with a Bartlein barrel on it which he installed/headspaced before sending it off to Masterclass Stocks to be fit to a stock.
I shot it for the first time last week, 20 rounds of Hornady 140 Gr A-MAX ammo, to get it sighted in, start getting used to the gun. Have about 200 rounds of Hornady brass, and 4 different high quality bullets to start reloading with.
However, today I inspected the brass I fired last week- again, Hornady factory rounds- and discovered that the primers were seriously flattened. To confirm- again, I'm a novice- I watched a few videos on YouTube that dealt with identifying high pressure condition indications on the primers.
My primers had no rounding whatsoever... they were completely flattened. Definite unsafe pressures according to everything I referenced to.
There were no indications like the bolt sticking- or tough extraction- and the brass itself in around the rim looked perfectly fine. Just the flattened primers.
Is this normal- to find factory ammo too hot???
Thanks for any advice.
Wes

[darkker]

Wes,
There are FAR to many stupidities and superstitions constantly being thrown around as fact.
Here is the reality, and here is what you need to know.

When it was decided that blowing things up on guesses want good enough they invented very carefully calibrated Lead Crushers, reporting LUP. As operating pressures rose, they were no longer accurate. So they moved to copper crushers, CUP. Again pressures rose, and in a very well publicized set of tests, it was shown that the same reference load reported pressures differing by 20,000 psi. So the world agreed that over about 45,000psi, copper crushers are not accurate. So we have moved on to Strain guage systems.
Since WWII there is NO cartridge company that publishes the alloy, or heat treatment specs of their brass. The last published alloy from Olin(who no longer makes any) was C260, which was spec'd to a tensile strength of @ 85,000 psi. So when you could measure brass expansion, you knew you were around 85,000 psi.

So, you have brass from an unknown alloy, primers from an unknown alloy. AND we know copper crushers can't accurately report current operating pressures. So why magically primers and brass are supposed to be accurate at Pressure reporting, is not only wrong; it needs to stop being repeated.

So what are you supposed to do? Buy a CHRONOGRAPH!!
Book data is all Pressure tested in SAAMI minimum spec equipment. Powders have a burning rate variation of around 10%. So ignore the specific grains listed, watch the velocity! Your production firearm has loser tolerances than the pressure testing. So you will never have identical velocities at the same Pressure. The difference is in the powders burning rate. Start at the start and work up under the chrono the whole time. When you see the difference in velocity change it exceed listed numbers, you know you have gone over Pressure.

A few other things to remember is that factory ammo (except Nosler) does NOT use canister grade powder (which is what we can buy).
Watch velocities. OR if you really want to know your specific rifle pressure, buy a Pressure Trace from RSI.
It is a strain guage system that allows you to see what is happening in YOUR rifle. Costs about the same as your rifle. Let's you see burning curves and Pressure spikes like these.
http://i78.photobucket.com/albums/j84/Darkker13/Mobile%20Uploads/Screenshot_2014-12-26-14-36-09_zpsv6lwcels.png
http://i78.photobucket.com/albums/j84/Darkker13/Mobile%20Uploads/Screenshot_2015-01-31-15-00-18_zpsmopqcu83.png

[yobuck]

Well ive been loading now for more than 65 years. For the last 45 years much of the loading has been for wildcat
cartridges where no published data exists. Untill recently, and by that ill say 20 years or so (most) reloaders didnt
own a chronagraph. I know shooters who have held records at 1000 yds who to this day still dont own a chronagraph.
Today with $100 units it seems everybodys gotta have one. Acurate loads (do not) require owning a chronagraph.
If you happen to be tech minded and just cant get enough of the tech information, then by all means buy a good one
and not a $100 one. As for pressure, listen to what the gun is telling you. A sticky bolt is definatly a sign its had enough.
As for flattened or cratered primers, get used to it. If thats the only signs your seeing i wouldnt be overly alarmed.
Ejector marks on the case head is another issue and when seeing those caution should be taken.
When i load for my long range guns im allways looking for the most i can get as for velocity.
I will start with a near max published load and load 1 round and then 1 each in half grain increases.
I simply shoot those at close range into a dirt bank. When i feel resistance on the bolt i stop right there.
Examine each case for ejector marks also. Thats my max for that particular powder/bullet combination.
I will then back off the load a half grain or more and work backwards with loads/seating depth looking for accuracy.
Ive found the max without wasting time and ammo.
Prior to loading i have jam seated a bullet into an unprimed empty case. I blacken the bullet and seat deeper
untill the rifling marks are no longer visable. Measure the oa legnth and increase it by 5 thou. I feel thats just
barly touching and where i start testing. I trust blackened bullets for legnth. Others can trust whatever they like.

[wbm]

Thanks Darkker. Very good information. Learn something every day....well if we really want too anyway.

[darkker]

That's the thing, if you want to. If you have nothing, something is better. So primers/brass is better than nothing, just not by much. Even a "cheap $100" chrono is several orders of accuracy better than primers/brass, for honestly knowing something other than "it dunn blowed-up".

Remember that "back in my day" we thought the world was flat. We thought that if you didn't believe in the same imaginary man in the sky, it was OK to burn people tied to a pole. We thought that a car that went faster than 35mph would likely rip your head off. We thought that if man was meant to fly he would have been born with wings.

There are always lessons to be learned from the past, but the more important thing to learn from them is their limited explanations of things.