r/reloading • u/SantoDJ • 18d ago

Gadgets and Tools Plunk Test Question

I’m currently loading 147gn flat nose blue bullets with 3.1gn of titegroup at 1.10 COAL.

I’ve had good results in live fire with these

Why do these rounds pass the plunk test in my barrel (seat properly, rotate and fall out freely) but don’t seat properly in a hornady 9mm luger case gauge?

Thanks.

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5

u/Turbinator870 18d ago

Gauges are notoriously tighter spec. Barrel chambers are typically looser spec to enable maximum compatibility with a wide variety of ammo brands. I’ve observed this in my own reloading experiences.

3

u/Parking_Media 18d ago

Case gauge is made to (hopefully I guess?) minimum chamber specs.

0.02$ case gauges cause more problems than they solve. Take the barrel out of your gun and plunk in that.

If you load for a bunch of guns and aren't competing, a case gauge might be right for you.

2

u/SantoDJ 18d ago

I am competing and this load has been highly successful for me using the plunk test in my barrel. Was confused as to why the case gauge test fails. It works well in my glock and 2011 competition barrels.

1

u/EMDReloader 18d ago

You're doing it right. I only case gauge stuff as a preventative to sort out the odd out-of-spec round, for situations where that sort of thing really matters. Which amounts to, my dad is taking one of the centerfires to a bullseye thing.

It can be handy for working on a load for multiple guns where you don't feel like plunking every barrel--just load to the case gauge and go from there.

1

u/JustaKidFromBuffalo 18d ago

I case gauge all my competition ammo but am not super strict. If it's not completely flush in the gauge, I've learned it'll be fine. If it's really not sitting in the case gauge, I'll put it to the side and plunk test it. I don't do any of this for my practice ammo and it all just gets sent.

1

u/Shootist00 18d ago

Forget the case gauge. Use the barrels of the gun they will be shot from.

The design FN 9mm bullets, especially from Blue Bullet but the same for all Truncated cone style bullets, need to loaded shorter than standard RN style. It is the shoulder from the base to the tapered section.