New Guy Question - working up a 9mm load for my pistols

[Shamr0ck]

As promised in my intro, here's another New Guy question....

Background
- I load on a Dillon 550
- I purchased the press in 2012-2013 when ammo supplies were tight and promptly got overrun with work, life and dad responsibilities so I'm really just digging in now...
- As component supply was just as bad as OEM ammo back in 2012/2013, I picked up what I could as I traveled and had a supply of Berry 115gr RN bullets, some mixed head stamp/once-fired brass and Power Pistol powder
- From: https://www.berrysmfg.com/faq#FAQ1 I have a top end velocity of 1,250 fps for these bullets
- From Hornady 9th, pg 771, 115gr RN bullet over Power Pistol has a charge range from 4.8gr@1,000 fps to 6.7gr@1,250 fps
- I want to build a single load which works safely in all my 9mm pistols
- I loaded up 10 rounds/pistol (all case gauged fine) and took them to the range recently.
- all fired fine, no strange report/recoil, no FTF/FTE
- I had marked the primers with a purple sharpie so I could ID them from the other empties on the range floor and I collected/bagged all the marked empties I could after each pistol and placed in a marked bag with the pistol used to fire them.

Load:
- Berry 115gr RN @ 0.356 #19355
- Power Pistol @ 5.6gr ( +- 1,100 fps per Hornday 9th, pg 771)
- Primer WSP
- COAL 1.100"

When I got home and inspected them, I noticed a couple of things:
- the primer strikes all looked good IMO - no flat primers or cratered primer strikes
- the cases fired thru the Walther PPQ/ H&K P30 all seemed to have a bottle neck shape to them now (like a 357sig). The cases all seem to bottleneck at roughly the same place.
- none of the empty cases fired from the PPQ/P30 drop all the way into a Wilson Case Gauge
- the cases fired thru the Sig 226 do not 'bottle neck' and look like a straight wall cartridge
- all but one of the Sig fired cases plunk into the case gauge. One doesn't quite plunk and sits just a bit proud of all the way in

Questions:
- Given no cycling issues and primers looking ok, is the 'bottle necking' of the cases in the P30/PPQ indicative of pressure issues or is it maybe caused by another issue? Neither of these pistols have many rounds thru them and are effectively brand new
- Can I use the bottle necked brass again or are they best placed in the recycle bin

If the bottlenecking is due to pressure issues in the PPQ/P30, I'll reduce the Powder charge and run the test again. I'm at a loss for what else it may be hence the question....


I'll add pix from my phone

PPQ case not plunking into case gauge




PPQ Cases- the cases all measure roughly 0.390 and then ‘neck down’ to roughly .38 at the case mouth


Load data

[Big Eddy]

Fired cases are not required to fit into a case guage until after they are sized. That is why we size them.
The “bottle necking” looks like a gun problem not an ammo problem. Do factory rounds do the same thing?
The cases will likely be OK to load after sizing and expanding the case mouth. The 9mm is not a straight walled case it is a tapered case.

[Shamr0ck]

Fired cases are not required to fit into a case guage until after they are sized. That is why we size them.
The “bottle necking” looks like a gun problem not an ammo problem. Do factory rounds do the same thing?
The cases will likely be OK to load after sizing and expanding the case mouth. The 9mm is not a straight walled case it is a tapered case.

Thanks for the reply.

I measured the cases before resizing given the difference in their appearance from the ones fired thru the Sig. Maybe the PPQ and P30 simply have larger chambers while the Sig's is tighter.

I will take some factory ammo with me the next time I head to the range and save the cases. From what I remember, fired factory cases looked 'normal' from both the PPQ/P30 but it bears confirmation. I'm enjoying the hobby and appreciate the assistance as I go thru the learning curve.

Have a great Labor Day weekend!

Cheers!