Thread: Pierced ginex primers

Had a surprise when I looked at some brass from a recent shoot. These were all loaded in virgin lapua brass with 25.7gr of 8208 behind a 130gr sierra game changer in a howa mini grendel.
This was a load that seemed to be fine previously, not running too hot according to the chrono and no heavy bolt lift when shooting these. Still knocked over the goats and possums just fine.
Not sure if these ginex primers are thin and blowing too easily, or if my powder scale (FA intellidropper) is inaccurate and throwing a few more spicy loads.
Has anyone else found the ginex small rifle primers are causing issues?

If that middle case did not have excessive headspace it was too hot. Powder can be temperature sensitive and be OK in winter....too hot in summer.

You need to check the headspace measurement on a fired case compared to an unfired one to begin the investigation.

The primer on the left and centre have a different appearance from each other. Are they the same primers and the same load? At first glance without any other info, this might indicate some kind of inconsistency of variables perhaps?

This was all new lapua brass, so the only treatment it got was a mandrel to straigten any bends in the mouth from shipping damage, then a very quick deburr/chamfer. I would expect that I shouldn't run into headspace issues with lapua brass? The rifle has gone through factory ammo with no issue, and this is near the end of 100 hand loads with no other issues so far.
These were all made as a batch together with the same lot of primers/powder/projectiles/brass, all to the same COAL with a hornady seater. The load was initially worked up a few months ago when it was colder, but this was not the hotest load and is a few grains off the book highest too.
I think I will need to invest in a good balance beam scale to keep some QC on the amount the powder scale is dropping

What is the action you are using here?

Oops I see you mentioned it . . . Howa Mini.

It might also pay to have your firing pin protrusion, diameter and fit to the firing pin hole checked. I havent heard of Howa's having issues with this atea but any manufactured item can have tolerance issues.

I think if the left and the middle are supposed to be the same loads you need to throw away whatever means you use to estimate charge weights.

Pretty sure someone mentioned thinner ginex primer cups on this forum a week or so ago. Was going to buy some and try out of interest when the shop opens.

Originally Posted by STC

I think if the left and the middle are supposed to be the same loads you need to throw away whatever means you use to estimate charge weights.

Yes, from left to right progressively higher pressure. Check/calibrate your scales

just by looking at the cases you'd think there were 3 different loads there...how do the current cases weigh up compared to cases you've previously used in the rifle?

Yes, definitely an increasing pressure problem. You need to check your scales and or powder thrower. Stop using and put aside and mark any more rounds you have left, including fired ones inspect, recycle them later. Start from scratch. Keep us posted on how you get on.

It has had several packets of factory ammo and nearing 100 handloads, I've kept all the brass and the only 2 unusual primers were the 1st and 3rd in the pic which are from the most recent batch, all the rest are similar to the middle primer. Thinking the powder scales need a check now

That middle primer looks flattened meaning excessive pressure. Did not hear good enough about Ginex to buy as an alternative to Federal.

What does the rest of the case look like? Dirty necks?