Thread: Flat primers

Hey all,

First reloading question of many I'd assume

Are some of these primers flatting out or am I being a bit paranoid?
Bolt isn't stiff to open and they are just over book OAL - shooting form a T3 .243 with 22" barrel

main reason I ask is I think I've got more velocity than book stated - going on bullet drop (need to get a chrony)



Looking at the photos they don't look as bad really

From the pictures you would have about ??? 1 more grain of powder before it starts to get there. Overall lenght is a relative thing and depends on the rifle .
I assume that it is 55gr projectiles , funny as ADI gives 45gr as a maximum and you're only at 41 .

If it was cold when you shot those rounds I would probably just leave it there if you are happy with the accuracy. When its Hot you might have more of a pressure issue.

They look fine to me.....I take more note of any stiff bolt lift or case head marking as primers are not a reliable indicator of pressure.

Ditto what veitnamcam said. Also primers can end up flat (with moderate loads) if your cases are a bit floppy in the chamber – usually with new brass in a larger than spec chamber or often after FLSing and pushing the shoulder back too far. Another check if you are getting up there a bit in load is to look at the punched out primers with a magnifying glass – if they are starting to look like a top hat then the pressure may be elevated.

I have been developing a load for a service rifle lately and at the range yesterday the primers looked flattish. When I got home and deprimed they were all still nicely radiused on the edges.

It is handy to have a wee manifying glass with you (left mine at home yesteray) and you will pick up early signs of brass flow into ejector holes etc that you may not see with the naked eye.

Cheers guys.

Yea sierra load data was about 45gr max

They were FLSed brass so will see how they look after only neck sizing

The thing to remember about reading pressure signs from primers is that a low pressure & high pressure load can both give flat primers . There are a lot of variables when fiquring out whether pressure is to "high " .

The indicators are not really that complex.

Here’s a situation that I have personally seen other shooters (plural events) up to –
Hammering the bolt open with a block of wood. (On some rifles the bolt handle will detach, which is probably a good thing as they cannot fire it again that day).

This can lead to one or two things – cannot get bolt open, trip to gunsmith, or gets bolt open, primer falls out of case.

Then firing another shot because they didn’t believe the symptoms of the first shot.

At this point it is necessary to intervene because they are firing right next to me and I was just trying to shut out external interruptions/influences/do my own thing, but my wellbeing was at risk.

I kid you not.

Was shooting in a competition, guy in group had a 7mm WSM? The primer fell out of every case on injection mentioned it, but he was happy. Didn't stand by him the rest of the day, just in case!!

I value my face and hands so I'm still pretty carefully with the whole process. have only loaded about 80 rounds so far but loving it

You can still see the brass stamping and there are no massive imprints of the extractor.
You are fine.