2 heavy bolt lifts and dirty cases

[stello1001]

Just tested some loads today. Had 2 cases on my last (highest charge) that had heavy bolt lift and they came out dirty. Specs below:

6.5 GRENDEL (howa mini bolt action)
Virgin starline
RUAG primers
107 TMK
benchmark powder

Cases were chamfered & deburred prior to running a mandrel through them.

I then primed with frankford hand primer seater.

Dumped a charge using chargemaster.

I will say though, these were new primers I was experimenting with. They went in super tight. It was pretty bad I almost thought they were going to perform so poor by how bad the fitment was. Mostly everything shot with extreme consistency as far as chrono numbers go.

I did 3 different charge weights with 5 rounds per with 107 SMK.
I also did the same with 107 TMK. The only 2 rounds with the issue were with the TMK on the last charge.

Charges went in the order below:

27.6
27.9
28.2

All 15 rounds with the 107SMK had insanely low ES & SD. The 107TMK had higher numbers but not too bad.

At the end, I fired 5 rounds with 107SMK and CCI450 as a control group since this was the first time trying the RUAG primers. The CCI450s did worse.

Below are the cases in question. I also noticed the top right corner case (this is also on the set with 2 cases in question) had what appears to be a micro crack right through the primer. I do not believe it leaked though.

Anyone had this happen before?

Thanks

 

[Dolomite]

It normally happens on lower charges. I do love the exotic lighting on the pictures.

 

[stello1001]

It normally happens on lower charges. I do love the exotic lighting on the pictures.

I shoot under a pink tent hahaha.

I thought so too, I figured on low charge cases where the brass does not fully expand to seal the chamber we get some gas leaking back out between chamber wall and case. However, do you believe this to be the case? I don't think it was too low a charge, and it only happened on the highest charge too. A bit strange.