Hey guys,

I am using Federal Gold Match magnum primers in my .280 Remington. The load is 58.5grs N550 and a 120gr GS Custom projectile. I am using Nosler Custom Brass

I have noticed that I am getting flat looking primers which some say is a sign of excess pressure. However, each of the cases fired exhibits the following:

1)No Sticky bolt lift.
2)Case head expansion is minimal.
3)Round edges on primer indentation, no sign of any cratering.
4)Cases show no sign of stretching.
5)Primer pockets still nice and tight.
6)Case head still perfect with no indentations from extractor.

Looking at some of the primers I have removed from my brass, shows a ridge around the top of the primer where the top of the primer has flowed out. This ridge is of a uniform nature.

I checked some .280 R/P cases that I had loaded 61.5 grs of H4350 in with 140 gr projectiles which is quite a bit over maximum that had been fired in the same rifle. In these cases, I was using standard Federal 210 primers, and these primers were still round on the edges. Once again, the same 6 signs as listed above.

Any ideas what is causing this? I was thinking maybe soft case head,

However, I will be dropping this load by 1/2 a grain down to 58. Also, next batch of reloads I will work up in my R/P Brass.



Regards,

Michael.

Well your right to be conserned about primer looks, but on their own they don't prove much.
I would definitely change primers to a standard and hard one like Win and try that.

Check the capacity of the Nosler brass to determine if it is different from the RP brass.

Sounds like everything is normal. A flat primer of itself does not indicate over pressure.
A primer goes through a few wild moves; When it fires it pushes the case forward the amount of the headspace and protrudes that amount.
When the pressure rises in the case it comes back over the primer. Some primers are softer, some are thiner, appearences may vary.
Good luck!

I would defer to our resident expert on CHE, Mr Hotcore. If you would measure a new case, fire it and measure it again, Mr Hotcore could tell you the exact pressure for that gun. You know, there is no more time-tested, accurate method for checking pressure than getting first hand info right from the cartridge case.

Just flag down Mr Hotcore and he'll solve your problem, I'm sure.

Federal primers have been known to have softer cups than other primers such as CCI or Winchester. I use a lot of Federal primers along with Winchester and Remington. In side by side comparisons between the 3, Federal primers almost always appear flatter.

It doesn’t bother me that Federal primers are soft, I just don’t rely on them that much for high-pressure signs. On the other hand though (IMO) if you truly flatten a CCI primer, I would say that you’re flirting with disaster.

Sounds like a bit of excess headspace to me. Are the cases new, or have they been full-length resized which may have pushed the shoulders back just a little?

While it is certainly possible to flatten primers with just high pressures, it's much more common to see them flattened by backing out a bit when fired, then getting squashed flat as the case stretches back to meet the bolt face.

Just one more thing to check on...

Steve,

Yes the brass was brand new.

Regards,


Michael.

Neck size the cases, and repeat the load with five cases. If you have the same result, worry. If not, it was a head space issue and the primers back out and were squashed. Kudude

"Any ideas what is causing this? "


Yep. It's excessive headspace due to the brass being too "short", from head to shoulder. Either neck sizing or "partial FL" sizing will fix it.

The "flat primer" concern was born back when most primers had convex heads. Assuming correct sizing, with today's flat head primers it doesn't show up much even if the loads are too hot.

And cratering is most often due to an oversized firing pin hole or a weak firing pin spring.

But sticky bolts and cuts on the case head tells the over pressure story, every time!

Thanks Kudude & Jim for your input on this.

I am really wondering if this is an excess headspace problem. The reason I say this is with my Federal brass and 140gr Remington Corelokts I loaded up to 61.5 grs H4350. I was using Federal 210 primers. I'm sure you will agree that is a load bordering on the excess pressure.

However, after firing these loads there was no sign of any excess pressure - including the primers still being round on the corners.

Also, when I brought my .280 I brought a box of factory Federal .280 ammunition and all the primers were nicely round after firing.


I'm however going to drop back 1/2 a grain and try the suggestions that Kudude mentioned, which is what I was thinking of trying anyway. See how I go from there.

I may even try a standard primer too.

Thanks again guys.

Michael.

"really wondering if this is an excess headspace problem"

Kiwi, doubt it is an "excess" of headspace, as such, just a stacking of tolerances between your rifle's chamber and your size die's chamber. It is likely they are both within normal factory tolerances. Such variations are safe for factory ammo, and even for reloads for a time, but eventually the cases will seperate just above the web.

As handloaders, such chamber slop won't matter if we adjust our sizers so the stretching is minimized and the cases will last a LOOONG time! Done properly, cases will eventually fail with harmless splits in the necks and that can be largely prevented by neck annealing every five or six loadings.

quote:

I am using Federal Gold Match magnum primers in my .280 Remington. The load is 58.5grs N550 and a 120gr GS Custom projectile. I am using Nosler Custom Brass

Muzzle velocity? Barrel length?

Gecko,

22 inch barrel, 3300 fps. The N550 load shows a 9.2% increase in velocity over the same weight of powder in H4350. Vhitavouri state that their 500 series powders give a 10% increase in velocity without increasing pressure. So, I am close to that claim.

Regards,

Michael.

The manufacturer, GS Custom, clearly recommends a maximum velocity of 3220fps out of a 24" barrel.

You are playing with fire in your 22" barrel and 3300fps

My experience with GS Custom bullets are that you stay within the maximum velocity limits as set by the manufacturer and firstly, reduce the velocity according to your specific rifles barrel length. (Roughly 50fps per 1" shorter barrel.)
Secondly, accept the muzzle velocity that your rifle yields without any - that includes the slightest little sign like a flat primer - as the maximum for the specific rifle.

With that in place, go out and hunt with the rifle and you will realize that you need no extra velocity since the performance you will get from the GSC bullet is already by far better than any other type of bullet available.

I managed to obtain some CCI 250 Magnum primers, which I believe are harder than Federal 215 Gold Match and loaded up 5 rounds with 58grs N550 (I cut back 1/2 a grain). Then I loaded up another 5 rounds also with 58grs N550 and a Federal 210 standard primer. I used Remington cases this time instead of the Nosler cases.

After firing, both the magnum primer and the standard primer were flat, however both primers still had rounded edges. Also on closer inspection of the primer after decapping it, there was no top hat look, the sides were perfectly parallel.

I miked the diameter of the primer pocket before and after, no change to the diameter.

However, the CCI 250's would not shoot a damn at all! A 5 shot group of 2.5 inches, compared to a 5 shot group of 0.783 for the standard primer. However I noticed a drop in velocity of 123 fps by using the standard primer.

When I loaded with Federal Gold Match magnum primers, I was getting 3316fps and a 5 shot group of around 3/4 of an inch. I asked 3 or 4 experienced reloaders at the range yesterday about their experiences with Federal Gold Match primers. All of them told me that they see Federal primers exhibiting the same characteristics as my loads even with loads not maximum by any stretch of the imagination.

It might also be worthy to note that the average capacity of my Remington brass was 2 grains more than the Nosler brass.

So, I think that I am going to go back to using the Federal primers for the velocity and accuracy, and use Remington brass. I feel confident that the load with 58grs of N550 is not a high pressured one. I would have been concerned if I saw the CCi 250's flat with a top hat look.

quote:

5)Primer pockets still nice and tight

As long as your primer pockets continue to stay nice & tight, you are OK pressure-wise. Pressures can only cause you real harm if they get out of the cartridge case and back into the action and your face. To do this, they first have to destroy the case head, and the path of least resistance to do this is through the primer/primer pocket!

This does NOT seem to be happening with your loads. I like to get at least ten reloads out of a batch of brass before I have to chuck them out due to loose primer pockets. Some folks I know are willing to get as little as five or six shots out of a case.

But please note that FLAT-APPEARING primers can be due to a number of causes other than excessive pressures. I believe Federal primers have a bit greater tendency to show flattening at normal pressure levels.

I'd say new brass with a bit of head space and possibly a slightly oversized firing pin hole. I'm gonna opine that the primer by itself is the least reliable of the watch me pressure signs. It has to be fairly dramatic or conjunct with other signs before I get too excited. You've still got rounded edges on the primers and no engraving on the face of the case. All your other signs are good. Not to worry.