Flattened primers from starting load to max

[GunAddict]

I am new to reloading. I am shooting 7mm Rem Mag. I started working a load 5 grains below the book max. I am getting flattened primers from starting load to max. Below are the three loads that I tried. Since this is a hunting rifle, I am loading .075" off of the lands.

#1
Fed 215 primer
Hornady 162 gr SST
57.5gr RL22

#2
60.3 gr RL22

#3
62.9 RL 22

Any ideas?

These are some of the #2 loads.

 

[jonbearman]

Yeah,you started at the top loads. You need to start near the bottom and work up slowly.60.3 and 62.9 are the stiffist loads.Start overfrom the bottom up.Didnt notice that you tried 57.0 or so,it shouldnt give you excess pressure.

 

[alf]

They don't look flat to me.....

The outside edge of the primer still has a good radius to it.

Primer appearance is just one indicator, it is not an end all......

Add in hard bolt lift and ejector marks, then you're there.

 

[gotcha]

If I understand you right..... you did start @ 57.5 then worked up to 62.9 ? Might get a rebuttal here but federals show me pressure sooner than other primers. As Alf says, I don't see excessive pressure yet. Assuming the cases are 1st time fired, do you plan on hd spacing from the belt or from the shoulder when you reload?

 

[GunAddict]

I'm not sure I know how to answer that question. When I FL size, I followed the instructions with the sizer die. I screw the sizer die to the shell holder and then go 1/8 to 1/4 more turns down.

I know that questions are a great way to learn. It just feels like a I keep asking very knowledgeable people stupid questions. All help is appreciated.

 

[tunered]

Take a fired case and chamber it, feel the resistance on the bolt, turn your FL die out till off the shell holder just a tad, full length the case you just tried in the gun, if still tight, run the die down 1/8 turn and start over, until there is smooth closing of the bolt, this will keep you from over working your brass. and headspacing off the belt.

 

[Elkbane]

G Addict,
Is this new brass, loaded for the first time? If so, IME, you'll almost always have "flatter" than normal primers on new, unfired brass. The reason is that the case hasn't been fireformed to your chamber yet, and has somewhat excessive headspace. WHat happens upon firing is the firing pin drives the case forward, then combustion takes place and the casehead is driven rearward against the bolthead. This rearward thrust can cause flattened primers, regardless of the load. After fireforming and setting up your dies properly, you should be able to use flattened primers as A pressure diagnostic symptom (but not the only one), but on first time fired cases, it can be deceiving.

Tunered gave good advise on setting up your dies. I personally prefer to measure what's going on with my cases rather than depend on the "feel" method. You'll need a "Stoney Point" headspace guage for that to attach to your calipers. You measure the case from head to datum point on the shoulder on a fired case, then keep adjusting your dies until you get a .0015 or .002 reduction in length on a sized case. This is the "shoulder bump" - how much you are reducing the case length from base to shoulder. I typically use .001 on target guns and .002-.0025 on hunting guns.

You may also want to measure some of your new unfired brass. You may be surprised at how much difference you see in unfired brass versus fireformed brass.

In my way of thinking, if you can only change what you can measure. And since managing uniformity is what we're really doing in reloading, it's worth the $ to invest in quality measurement tools.
Elkbane

 

[GunAddict]

This once once fired Hornady brass. So this was my first loading. I am thinking that my first FL size may have been the problem. When I first received my dies, I was eager to get going without understanding the process enough. I sized them 1/4 turn down from shell holder contact. So I probably had excessive headspace.

Thanks for all the help. The more I learn, the more I realize how little I know. As long as I keep learning and improving I should be alright.

 

[300 RUM]

In the photo you supplied , you can see around the primer, the edge still has a radius like alf stated. If you were getting flat primers you would not be able to see the side of the primer. flattened primers have a very nice 90deg corner to them.

 

[jo191145]

I'm not sure I know how to answer that question. When I FL size, I followed the instructions with the sizer die. I screw the sizer die to the shell holder and then go 1/8 to 1/4 more turns down.

Therein lies your problem. NEVER follow the generic one size fits all instructions that come with most FL dies. They're dangerously incorrect.
You need the ability to measure your rifles specific headspace and set the die accordingly.
Headspace should be lesson #1 on page #1 of any reloading manual IMO (if I ran the world ;D ).
Knowledge of headspace is a must, everything else in the book is just tweaking.
Don't feel bad, I and most others learned or were taught the same way.

 

[BoydAllen]

First of all get one of the caliper attachments for measuring case "headspace". Then, just for fun, measure a new case, a fired case, and, if you have any left, one that you sized, and get back to us. When we are looking at shoulder bump, I like to have a case that has been fired more than once, without any bumping, as a reference, rather than the dimension that you will get from once fired brass. Another thing worth remembering is that a full turn of a die advances it into the press about .071, so when you start playing with die settings, remember that turning it an eighth of a turn is a smidge less than .009. Before you measure a fired case, either deprime it, or reseat the fired primer so that no part of it is above the case head....even a little.

 

[GunAddict]

I took the advice and bought the Hornady headspace gauge. I compared the fired cases to some of the FL sized cases. It looks like the shoulder was bumped back .005" to .007".

 

[watercam]

Guys, he is loading a magnum cartridge that headspaces on the BELT. Shoulder headspace does not matter with regard to his primers. Yes, you want minimum shoulder bump for best accuracy and less brass working. However, the belted magnum can be safely fired with excess shoulder clearance because it headspaces on the belt first.
To answer you question your primers look OK, Federal primers do have softer cups I think. Other pressure signs are:
Stiff bolt handle lift (major indication - drop a whole grain)
Smear marks on the bottom of the case head indicates brass flowing into the ejector hole (drop a whole grain)
Major spikes in velocity vs. even velocity gains per grain increase
Let us know how it goes for you!