Over pressure?
- Thread starter jojo4711
- Start date
Pond James Pond
New member
I am really not an expert, but the 9mm cases look as though pressure has pushed them into the firing pin hole as there seems to be bulging around the primer strike.
It seems most visible on the 3 on the right side of the first picture.
On the flip side, when I read about powder residue, i though "unburnt powder" and then I thought "low pressure"
So clearly one of my observations is wrong!!
I can see nothing wrong with the rifle cartridges, though.
It seems most visible on the 3 on the right side of the first picture.
On the flip side, when I read about powder residue, i though "unburnt powder" and then I thought "low pressure"
So clearly one of my observations is wrong!!
I can see nothing wrong with the rifle cartridges, though.
The outside edges of the primers in the 9 mm ammo are very rounded, so there is not enough pressure to injure them. The impression in the center is due to the particular weapon's breech face design. The slightly oblong firing pin indentation is the result of a the pin not being fully retracted by the time the barrel starts to unlock, which is not uncommon.
All 9mm was shot with glock 19 and I checked factory rounds I shot that day, they have the same indentation on the primer. So I need higher pressure? I used 115gr hornady xtp with 5.4gr Winchester autocomp. From top to bottom they were loaded to 1.135", 1.130", 1.125", 1.120". So I either need more powder (max load is 5.6gr) or load to lower depth to gain more pressure? Recommended COL is 1.125 according to Hornady.
Jojo,
You can try the max load. I'm guessing your chamber is generous enough that you will have to run over published maximum to reach the same pressure and velocity the test gun did, though. The slower burning a powder is, the easier it is to run into that problem.
Looking at Hodgdon's burn rate chart, your Autocomp is between HS-6 and CFE Pistol. Both on the slow end for anything but +P loads with a 115 grain bullet, IMHO. If you look at Hodgdon's load data sight, note that HP-38/231 (same powder with different branding) will get you to the same velocity with smaller charge weights. That's a good sign your powder choice is a bit too slow burning for clean operation in your chambering. I think you'd be happier with those powders. If you are willing to let go of 10 or 20 fps and can find some, Hodgdon Universal would be your best choice for clean burning.
You can try the max load. I'm guessing your chamber is generous enough that you will have to run over published maximum to reach the same pressure and velocity the test gun did, though. The slower burning a powder is, the easier it is to run into that problem.
Looking at Hodgdon's burn rate chart, your Autocomp is between HS-6 and CFE Pistol. Both on the slow end for anything but +P loads with a 115 grain bullet, IMHO. If you look at Hodgdon's load data sight, note that HP-38/231 (same powder with different branding) will get you to the same velocity with smaller charge weights. That's a good sign your powder choice is a bit too slow burning for clean operation in your chambering. I think you'd be happier with those powders. If you are willing to let go of 10 or 20 fps and can find some, Hodgdon Universal would be your best choice for clean burning.